A 6-blade turbine agitator with a diameter of 1.5ft is used to mix a A 6-blade turbine agitator with a diameter of 1.5ft is used to mix a solution with a viscosity of 10cP and a density of 95lb/ft
solution with a viscosity of 10cP and a density of 95lb/ft33. N=120rpm.. N=120rpm. Calculate the theo horsepower required if the tank is provided with Calculate the theo horsepower required if the tank is provided with 4baffles.
4baffles. 2hp.2hp.
A double-flight helix impeller 3ft diameter and 3ft high is operating at A double-flight helix impeller 3ft diameter and 3ft high is operating at 30rpm in a 3.2ft diameter tank. 85% full, 1000poise and 65lb/ft 30rpm in a 3.2ft diameter tank. 85% full, 1000poise and 65lb/ft33.. Estimate hp requirement.
Estimate hp requirement. 7hp7hp
A mixing tank set-up that follows curve 2 of Fig. 18-17 Perry, 8/ed. Is A mixing tank set-up that follows curve 2 of Fig. 18-17 Perry, 8/ed. Is using vertical blades of H=3in. Width of each baffle.
using vertical blades of H=3in. Width of each baffle. 6inches.6inches.
A three-blade propeller is used to mix a fluid in the laminar region. A three-blade propeller is used to mix a fluid in the laminar region. D
Daa=0.3m; N=1.5Hz. If flat two-bladed paddle D=0.3m; N=1.5Hz. If flat two-bladed paddle Daa=0.75m. What is N.=0.75m. What is N. 24rpm
24rpm
An agitation vessel is equipped with a turbine impeller having a An agitation vessel is equipped with a turbine impeller having a diameter of 30cm. density=1000kg/m
diameter of 30cm. density=1000kg/m33; viscosity=1x10; viscosity=1x10-3-3 Pa-s; Pa-s; N=100rpm. What is N
N=100rpm. What is NRe.Re.150,000150,000
An agitator with a diameter of 2ft and a speed of 100rpm is mixing An agitator with a diameter of 2ft and a speed of 100rpm is mixing rubber-latex compound with a viscosity of 1250 poise and a density of rubber-latex compound with a viscosity of 1250 poise and a density of 70lb/ft
70lb/ft33. The N. The N Re
Re for the mixing operation is for the mixing operation is 5.56 5.56
An industrial mixing tank uses a 1.5ft diameter impeller operating at a An industrial mixing tank uses a 1.5ft diameter impeller operating at a speed of 120rpm. If 1000rpm, D
speed of 120rpm. If 1000rpm, Daaisis 6inches..6inches.. Decreasing the shape factor, S
Decreasing the shape factor, S11, the ratio of the impeller to the tank, the ratio of the impeller to the tank diameter D
diameter Daa/D/Dtt, when the baffles are few and narrow will, when the baffles are few and narrow will increase theincrease the power requirement.
power requirement.
Following the “standard” proportions in the design of a
Following the “standard” proportions in the design of a 66-blade turbine-blade turbine agitator, if an impeller has a diameter of 20cm, what would be the agitator, if an impeller has a diameter of 20cm, what would be the recommended tank diameter and the depth of the liquid in the tank, in recommended tank diameter and the depth of the liquid in the tank, in cm.
cm. 60cm, 60cm.60cm, 60cm.
For a pitched-blade turbine agitator, increasing the shape factor, S For a pitched-blade turbine agitator, increasing the shape factor, S22 defined as the clearance from the bottom of the tank, E/ D
defined as the clearance from the bottom of the tank, E/ Dtt, the power, the power requirement will
requirement will decrease.decrease.
If the set-up given in prob. 18 is to mix a solution with a viscosity of 5 If the set-up given in prob. 18 is to mix a solution with a viscosity of 5 cP and a density of 65lb/ft
cP and a density of 65lb/ft33, what will be the hp requirement if , what will be the hp requirement if the speedthe speed of the impeller is 60rpm.
of the impeller is 60rpm. 3.3hp.3.3hp.
If the tank in Prob. 9 is unbaffled, what will be the power requirement. If the tank in Prob. 9 is unbaffled, what will be the power requirement. 0.42hp.
0.42hp.
If the viscosity of the liquid i
If the viscosity of the liquid i s reduced by ½ due to heating of the liquids reduced by ½ due to heating of the liquid inside the tank, what will be the percentage reduction in the power inside the tank, what will be the percentage reduction in the power requirement.
requirement. 54%.54%. In agitation, for N
In agitation, for NReReof 1000, the power requirement in a baffled tank isof 1000, the power requirement in a baffled tank is approx.
approx. 55%55% per cent higher/lower than in per cent higher/lower than in unbaffled tank.unbaffled tank.
In the motion of the impeller blades against the liquid in the mixing tank, In the motion of the impeller blades against the liquid in the mixing tank, the force acting perpendicular to the surface of the impeller is referred the force acting perpendicular to the surface of the impeller is referred to as
to as drag force.drag force.
In the use of turbines for low-viscosity liquids, rapid currents that In the use of turbines for low-viscosity liquids, rapid currents that destroys stagnant pockets occur. N
destroys stagnant pockets occur. Near the impeller.ear the impeller. It is desired to agitate a liquid having a viscosity of 1.5x10
It is desired to agitate a liquid having a viscosity of 1.5x10-3-3Pa-s and aPa-s and a density of 969 kg/m
density of 969 kg/m33 in a tank in a tank having a diameter of 0.91m. W= having a diameter of 0.91m. W= 0.0381.0.0381. Calculate the required kW.
Calculate the required kW. 0.190kW 0.190kW
One effective method of preventing vortex formation in a mixing tank One effective method of preventing vortex formation in a mixing tank where the shaft of the impeller is vertical, is to
where the shaft of the impeller is vertical, is to install baffles.install baffles.
Referring to prob.18, what will be the power requirement if the speed is Referring to prob.18, what will be the power requirement if the speed is increased to 80rpm.
increased to 80rpm. 7.8 hp7.8 hp
Referring to prob.18, what will be the power requirement if the speed i Referring to prob.18, what will be the power requirement if the speed i ss reduced to 10rpm.
reduced to 10rpm. 2.3hp2.3hp
Relatively, the shape of the mixing tank, say cylindrical compared to a Relatively, the shape of the mixing tank, say cylindrical compared to a square or rectangular tank, has practically no effect on the power square or rectangular tank, has practically no effect on the power requirement.
requirement. True.True.
The dimensionless number that describes the effect of wave motion on The dimensionless number that describes the effect of wave motion on the surface of a liquid especia
the surface of a liquid especia lly in agitation and mixing is lly in agitation and mixing is expressed inexpressed in terms of
terms of Froude number. Froude number.
The velocity components induced by the rotation of the impeller in the The velocity components induced by the rotation of the impeller in the mixing process tends to induce the formation of vortex and swirling. mixing process tends to induce the formation of vortex and swirling. These velocity components are
These velocity components are tangential and radial.tangential and radial.
Using the data given in prob.15 and referring to Fig.18-17 Perry 8/ed, Using the data given in prob.15 and referring to Fig.18-17 Perry 8/ed, determine the power requirement if the mixing system is described by determine the power requirement if the mixing system is described by curve. 5.
curve. 5. 5 hp.5 hp.
What will be the recommended volume of the solution to be charged in What will be the recommended volume of the solution to be charged in the mixing tank given in prob.18. Neglect the volume occupied by the the mixing tank given in prob.18. Neglect the volume occupied by the mixer and baffles.
mixer and baffles. 170ft 170ft 33
When blending two or more flammable liquids in a
When blending two or more flammable liquids in a tank, it is appropriatetank, it is appropriate to use
to use jet mixers. jet mixers.
When strong vertical currents in the mixing tank is desired, it is best to When strong vertical currents in the mixing tank is desired, it is best to use
use propellers propellers When the N
When the NReRein a mixing tank is less than 10, the flow is consideredin a mixing tank is less than 10, the flow is considered laminar. In this range, the property that becomes unimportant in laminar. In this range, the property that becomes unimportant in determining the power requirement is
determining the power requirement is density of fluid.density of fluid.
20% Oleum means that in 100lb, there are 20lb of
20% Oleum means that in 100lb, there are 20lb of SOSO33 and 80lb of and 80lb of H
H 22SOSO4.4. 90% of the NH
90% of the NH33 entering an NH entering an NH33-oxidation unit is converted to HNH-oxidation unit is converted to HNH33 and 10% loss of NH
and 10% loss of NH33is due to conversion losses, NO in is due to conversion losses, NO in the stack gasesthe stack gases and miscellaneous losses. Kg of NH
and miscellaneous losses. Kg of NH33 necessary to produce 60,000 kg of necessary to produce 60,000 kg of 62 wt% HNO
62 wt% HNO33 is is 12,000.12,000.
A 20% aqueous sol’n of Na2CO3 and 25% aqueous sol’n of Ca(OH)2 A 20% aqueous sol’n of Na2CO3 and 25% aqueous sol’n of Ca(OH)2 were reacted to produce caustic soda sol’n. Precipitate contains 5% H were reacted to produce caustic soda sol’n. Precipitate contains 5% H22O,O, 1% NaOH, 94% CaCO
1% NaOH, 94% CaCO33. The conc. Of NaOH sol’n p. The conc. Of NaOH sol’n p roduced isroduced is 10.97%.10.97%. A cement clinker with the ff analysis: Cao=64%, SiO
A cement clinker with the ff analysis: Cao=64%, SiO22=21%, Fe=21%, Fe22OO33 and and Al
Al22OO33. The MT of silica required for a 300-day operation per year is. The MT of silica required for a 300-day operation per year is 20,000.
20,000.
A cement company uses 3000MT of gypsum a month. Portland cement, A cement company uses 3000MT of gypsum a month. Portland cement, the MT clinker produced monthly by the cement plant is
the MT clinker produced monthly by the cement plant is 75,000.75,000. A plant near Maria Cristina Falls is to manufacture NH
A plant near Maria Cristina Falls is to manufacture NH33 by using a by using a stoichiometric mixture of N
stoichiometric mixture of N22and Hand H22. The moles of H. The moles of H22 present present in in thethe mixture if 100mol of pure electrolytic H
mixture if 100mol of pure electrolytic H22is used isis used is 84.95 moles.84.95 moles. A water solution of molasses contains 10% by weight sucrose A water solution of molasses contains 10% by weight sucrose (C
(C1212HH2222OO1111). The weight percent of C). The weight percent of C22HH66O in the sol’n after 90% O in the sol’n after 90% of theof the sucrose has been converted to C
sucrose has been converted to C22HH66O by fermentation is 5.1%.O by fermentation is5.1%. An analysis of the
An analysis of the gases entering the converter of an ammonia gases entering the converter of an ammonia oxidationoxidation nitric acid plant indicates that the gases contain 0.066lb of NH nitric acid plant indicates that the gases contain 0.066lb of NH33 and and 0.934lb of air per pound of gas. 1lb of the gas leaving the converter 0.934lb of air per pound of gas. 1lb of the gas leaving the converter contains 0.00361lbmol of NO (no NO
contains 0.00361lbmol of NO (no NO22). % NH). % NH33 converted to NO is converted to NO is 93%.
93%.
At a plant which produces H
At a plant which produces H22SOSO44 by the contact process, a large storage by the contact process, a large storage tank currently holds 100,000kg of 20% oleum,
tank currently holds 100,000kg of 20% oleum, where 20% oleum meanswhere 20% oleum means that in 100kg of material
that in 100kg of material there is 20kg of SO3 dissolved ithere is 20kg of SO3 dissolved i n 80kg of puren 80kg of pure H
H22SOSO44. The weight percent H. The weight percent H22SOSO44 in the final mixture in the tank is in the final mixture in the tank is 80.4%.
80.4%.
Bauxite containing 61% Al
Bauxite containing 61% Al22OO33 and 8% SiO and 8% SiO22 is roasted and dissolved in is roasted and dissolved in caustic soda to form a solution from which iron present is precipitated caustic soda to form a solution from which iron present is precipitated and filtered out. The cost of caustic soda needed to produce 1000kg of and filtered out. The cost of caustic soda needed to produce 1000kg of pure Al
pure Al22OO33assuming 10% more than the tassuming 10% more than the t heo amount of NaOH neededheo amount of NaOH needed is used.
is used. P 6065. P 6065.
Bio-degradable detergents
Bio-degradable detergents can be readily oxidized.can be readily oxidized. Builders are added to soap to
Builders are added to soap to boost cleaning power.boost cleaning power.
AGITATION AGITATION
CPI CPI
Catalyst used in hydrogenation of oil is Catalyst used in hydrogenation of oil is Nickel. Nickel.
Catalysts used in the manufacture of sulfuric acid by chamber and Catalysts used in the manufacture of sulfuric acid by chamber and contact processes are respectively
contact processes are respectively oxides of nitrogen and V oxides of nitrogen and V 22OO55on aon a porous carrier.
porous carrier.
Cement mainly contains
Cement mainly contains Cao, SiOCao, SiO22 , Al , Al 22OO3.3.
Coefficient of thermal expansion of glass is decreased by the addition Coefficient of thermal expansion of glass is decreased by the addition of
of ZnO ZnO during its manufactureduring its manufacture.. Contact process
Contact process yields yields acid acid of of higher higher concentration concentration than than chamberchamber process.
process.
Cumene is the starting material for the production of
Cumene is the starting material for the production of phenol a phenol and acetonend acetone Economics of “Solvay Process” depends upon the efficiency of Economics of “Solvay Process” depends upon the efficiency of ammonia recovery and size of plant.
ammonia recovery and size of plant. Enamels
Enamels give good glossy finish give good glossy finish Essential oils are usually obtained using
Essential oils are usually obtained using steam distillation. steam distillation. Fat splitting catalyst is
Fat splitting catalyst is ZnO. ZnO. Free alkali in toilet soap is
Free alkali in toilet soap is less than that in a laundry soap.less than that in a laundry soap. Function of thinner in a paint is to
Function of thinner in a paint is to suspend pigments and dissolve film- suspend pigments and dissolve film- forming materials.
forming materials. Fusion of bauxite and
Fusion of bauxite and Limestone Limestone produces high alumina cement. produces high alumina cement. Glauber’s salt is
Glauber’s salt is sodium sulfate decahydrate. sodium sulfate decahydrate. Gypsum is
Gypsum is calcium sulfate.calcium sulfate. Hydrazine is largely used
Hydrazine is largely used as rocket fuel.as rocket fuel. In a liquid Cl
In a liquid Cl22 plant, chlorine gas with some H plant, chlorine gas with some H22gas is liquefied, with partgas is liquefied, with part of the Cl
of the Cl22made to form HCl, according to the ff diagram. The Clmade to form HCl, according to the ff diagram. The Cl22sentsent to synthesis plant in MT is
to synthesis plant in MT is 22.7.22.7. In contact process, SO
In contact process, SO33, is absorbed in 97% H, is absorbed in 97% H22SOSO44 and not in water and not in water because
because water forms an acid mist which is difficult to absorb.water forms an acid mist which is difficult to absorb.
In the lime soda process for caustic soda manufacture, lime is made to In the lime soda process for caustic soda manufacture, lime is made to react with water and then with soda ash. The metric tons of lime that react with water and then with soda ash. The metric tons of lime that will be needed t
will be needed t o produce 100MT of 25% liquid NaOH iso produce 100MT of 25% liquid NaOH is 31.21 MT.31.21 MT. In the Lurgi coal gasifier
In the Lurgi coal gasifier large quantity of coal can be processed.large quantity of coal can be processed. Metallic soap is
Metallic soap is aluminum or calcium salt of fatty acids.aluminum or calcium salt of fatty acids. Oil is
Oil is a mixture of glycerides of fatty acids.a mixture of glycerides of fatty acids. Oxygen is produced by fraction of air using
Oxygen is produced by fraction of air using both Linde’s and Claude’sboth Linde’s and Claude’s process.
process.
Permanent hardness of water is due to the presence of calcium and Permanent hardness of water is due to the presence of calcium and magnesium
magnesium sulfates and chlorides. sulfates and chlorides. Plasticizers are added to paints to
Plasticizers are added to paints to give elasticity and give elasticity and prevent cracking ofprevent cracking of the film
the film
Producer gas consists mainly of
Producer gas consists mainly of CO, COCO, CO22 , N , N 22 , H , H 22.. Rancidity of oil can be reduced by
Rancidity of oil can be reduced by hydrogenation.hydrogenation.
Raw materials for “Solvay Process” for manufacture of the soda ash are Raw materials for “Solvay Process” for manufacture of the soda ash are salt, limestone, ammonia, and
salt, limestone, ammonia, and coke oven gas.coke oven gas. SO
SO22is bubbled through hot sugar-cane juice tois bubbled through hot sugar-cane juice to act as an acidifying agent act as an acidifying agent Soap cannot be used with hard water because
Soap cannot be used with hard water because they form insolublethey form insoluble calcium soaps which precipitate.
calcium soaps which precipitate. Solvent used for extraction of oil is
Solvent used for extraction of oil is methyl ethyl ketone.methyl ethyl ketone.
The catalyst used in the manufacture of DDT from chloral and The catalyst used in the manufacture of DDT from chloral and chlorobenzene is
chlorobenzene is oleum.oleum.
The electrolytic reaction for the production of aluminum may be written The electrolytic reaction for the production of aluminum may be written as Al
as Al22OO33 + 3/2 C + 3/2 C 2Al + 3/2 CO 2Al + 3/2 CO22, 235,000cal of energy (in the form, 235,000cal of energy (in the form of electricity) is consumed for the production of 2gmol of Al. Amount of electricity) is consumed for the production of 2gmol of Al. Amount to be paid for elec. power per lb Al produced is
to be paid for elec. power per lb Al produced is P 0.066/lb Al. P 0.066/lb Al. The main use of HCl is in the
The main use of HCl is in the drilling of petroleum wells and picklingdrilling of petroleum wells and pickling of steel sheets.
of steel sheets. The MT of CaCO
The MT of CaCO33needed to produce 100MT of soda ash daily by theneeded to produce 100MT of soda ash daily by the Solvay process is
Solvay process is 93.34.93.34. Trinitro-toluene is
Trinitro-toluene is an explosive.an explosive.
Unsaturated oils compared to saturated oils have
Unsaturated oils compared to saturated oils have lower melting pointlower melting point and higher reactivity to oxygen.
and higher reactivity to oxygen.
Using the data given below, the metric tons of rock phosphate Using the data given below, the metric tons of rock phosphate (CaFCa
(CaFCa44(PO(PO44))33) needed to produce 6000MT of 90% purity) needed to produce 6000MT of 90% purity superphosphate is
superphosphate is 9530.9530. Varnish does not contain
Varnish does not contain pigment. pigment. Wax is
Wax is a mixture of esters of polyhydric alcohols except glycerin.a mixture of esters of polyhydric alcohols except glycerin. Which is the main reducing agent during the production of iron from Which is the main reducing agent during the production of iron from iron ore in a blast furnace.
iron ore in a blast furnace. COCO
Which of the ff is the common pollutant emitted from metallurgical Which of the ff is the common pollutant emitted from metallurgical smelters, thermal power plant and cement plants.
smelters, thermal power plant and cement plants. SOSO22 Which of the following is a detergent.
Which of the following is a detergent. Alkyl benzene sulfonate. Alkyl benzene sulfonate. Which oil is preferred for paint manufacture.
Which oil is preferred for paint manufacture. Drying oil Drying oil Widely used method for conditioning of boiler feed water is
Widely used method for conditioning of boiler feed water is hot-limehot-lime soda process.
soda process.
Yellow glycerin is made into white, using
Yellow glycerin is made into white, using activated carbon.activated carbon. Zeolite removes both temporary as
Zeolite removes both temporary as well as permanent hardness of waterwell as permanent hardness of water by precipitating
by precipitating calcium and calcium and magnesium present in magnesium present in water as water as insolubleinsoluble zeolites.
zeolites. Sodium chloride.Sodium chloride.
A continuous re-circulating aerobic biochemical process that keeps cells A continuous re-circulating aerobic biochemical process that keeps cells in suspended growth
in suspended growth activated sludge process.activated sludge process.
A global treaty that aims to diminish and eventually phase out CFCs. A global treaty that aims to diminish and eventually phase out CFCs. Montreal protocol
Montreal protocol
A global treaty that aims to protect human health and the environment A global treaty that aims to protect human health and the environment from the persistent organic pollutants.
from the persistent organic pollutants. Stockholm ConventionStockholm Convention
A global treaty that aims to regulate emissions of greenhouse gases. A global treaty that aims to regulate emissions of greenhouse gases. Kyoto Protocol
Kyoto Protocol
A neurological disease characterized by trembling, inability to walk A neurological disease characterized by trembling, inability to walk andand speak and even serious convulsions that can lead to death due to speak and even serious convulsions that can lead to death due to ingestion of mercury
ingestion of mercury minimata.minimata.
A phenomenon where a cold layer of air becomes
A phenomenon where a cold layer of air becomes trapped by a layer oftrapped by a layer of warmer air above due to a lack of wind circulation or the presence of warmer air above due to a lack of wind circulation or the presence of certain topographical features, such as mountains, resulting to air certain topographical features, such as mountains, resulting to air pollution being trapped
pollution being trapped in the lower, in the lower, cooler layers of cooler layers of the troposphere.the troposphere. Thermal inversion
Thermal inversion
A stack in an urban area is emitting 80g/s of NO. It has a
A stack in an urban area is emitting 80g/s of NO. It has a n effective stackn effective stack height of 100m. Estimate the ground level conc. At 2km downwind on height of 100m. Estimate the ground level conc. At 2km downwind on the centerline.
the centerline. 63.7 microgram/m63.7 microgram/m33
A trace metal which causes Itai-itai disease is
A trace metal which causes Itai-itai disease is cadmium.cadmium. A wastewater with a BOD/COD = 1 indicates that
A wastewater with a BOD/COD = 1 indicates that biological treatmentbiological treatment is most practical.
is most practical.
A water sample was analyzed to contain 150mg-L A water sample was analyzed to contain 150mg-L-1-1COCO
3
3-2-2 and 100 -L and 100 -L --1
1HCOHCO 3
3-2-2 at a pH of 8.00 at 25 at a pH of 8.00 at 25OOC. Total alkalinity in terms of CaCOC. Total alkalinity in terms of CaCO33 is is 332ppm.
332ppm.
Aeration of water is done
Aeration of water is done to removeto remove dissolved gases.dissolved gases.
An electrochemical process used in the removal of colloidal matter in An electrochemical process used in the removal of colloidal matter in wastewater through reduction of electrostatic charges surrounding the wastewater through reduction of electrostatic charges surrounding the solids is called
solids is called coagulation.coagulation.
Biomes are distinguished or identified by its
Biomes are distinguished or identified by its dominant plant life.dominant plant life. Calculate the
Calculate the theo oxygen demand (ThOD) of 150ppm glucose.theo oxygen demand (ThOD) of 150ppm glucose. 160ppm160ppm Class of water intended for primary contact recreation such as bathing, Class of water intended for primary contact recreation such as bathing, swimming, skin diving, etc.
swimming, skin diving, etc. Class BClass B Component of CFC
Component of CFC’s that causes destruction of 100,000 molecules of’s that causes destruction of 100,000 molecules of ozone.
ozone. chlorinechlorine
Denitrification is carried out when bacteria break down nitrates and Denitrification is carried out when bacteria break down nitrates and release nitrogen gas. What are these bacteria.
release nitrogen gas. What are these bacteria. Anaerobic bacteria. Anaerobic bacteria.
ENVIRONMENTAL ENGINEERING ENVIRONMENTAL ENGINEERING
During which of the ff operating conditions of an automobile CO During which of the ff operating conditions of an automobile CO content in the exhaust gas is maximum
content in the exhaust gas is maximum idle running.idle running.
Ecological Solid Waste Management Act of 2000 is otherwise known Ecological Solid Waste Management Act of 2000 is otherwise known as
as RA 9003 RA 9003
For a given temperature profiles, determine which profile is neutrally For a given temperature profiles, determine which profile is neutrally
stable. stable.11
From question no. 15, estimate the ground level conc. At 2km From question no. 15, estimate the ground level conc. At 2km downwind, 0.1 km off the centerline.
downwind, 0.1 km off the centerline. 60microgram/m60microgram/m33 Gas responsible for the rotten egg of waste water.
Gas responsible for the rotten egg of waste water. Hydrogen sulfide. Hydrogen sulfide. Generic term used to describe the particulate matter carried in the Generic term used to describe the particulate matter carried in the effluent gases from furnaces burning fossil fuels
effluent gases from furnaces burning fossil fuels fly ash. fly ash. Hardness of water is usually expressed as parts per million of
Hardness of water is usually expressed as parts per million of CaCOCaCO33.. If the three-day BOD (BOD
If the three-day BOD (BOD33) of a raw sewage is ) of a raw sewage is 55ppm (k=0.55/day),55ppm (k=0.55/day), what is the ultimate BOD.
what is the ultimate BOD. 68ppm68ppm
Insufficient washing of sand grains in a rapid sand filter causes Insufficient washing of sand grains in a rapid sand filter causes mudmud balls.
balls.
Involves the accumulation of trace metals through each species of the Involves the accumulation of trace metals through each species of the food chain.
food chain. Biomagnification. Biomagnification.
It is a phenomenon that results in the overabundance in the algae growth It is a phenomenon that results in the overabundance in the algae growth in bodies of water. It is also the natural process of nutrient enrichment in bodies of water. It is also the natural process of nutrient enrichment that occurs over time in a body of water.
that occurs over time in a body of water. Eutrophication. Eutrophication.
It is a very unstable gas used for disinfection, a very powerful oxidant It is a very unstable gas used for disinfection, a very powerful oxidant capable of oxidizing 200 to 300 times more than chlorine and can reduce capable of oxidizing 200 to 300 times more than chlorine and can reduce complex taste, odor and color
complex taste, odor and color ozone.ozone.
It is defined as the controlled decomposition of organic materials, such It is defined as the controlled decomposition of organic materials, such as leaves, grass, and
as leaves, grass, and food scraps.food scraps. composting composting
It is defined as the role of the organisms in the community. It is defined as the role of the organisms in the community. Niche. Niche. It is described as the c
It is described as the c loud of air pollution trapped by thermal inversion.loud of air pollution trapped by thermal inversion. smog
smog It is used a
It is used a s bonding agents in building and furniture construction whichs bonding agents in building and furniture construction which may cause drowsiness, nausea and headaches
may cause drowsiness, nausea and headaches when exposed to low levelwhen exposed to low level concentration.
concentration. formaldehyde formaldehyde
Legislation that presents the revised water usage and classification. Legislation that presents the revised water usage and classification. DENR AO no. 34.
DENR AO no. 34.
Maximum allowable concentration of CO
Maximum allowable concentration of CO22 in air for safe working is in air for safe working is 5000
5000 ppm. ppm.
Most aquatic organisms can
Most aquatic organisms can survive in pH range of aboutsurvive in pH range of about 6 to 9.6 to 9. Most commonly used coagulating agent.
Most commonly used coagulating agent. Aluminum sulfate. Aluminum sulfate. Nitrates
Nitrates more more than than 50ppm 50ppm in in water water leads leads to to a a disease disease calledcalled mathenoglobenemia.
mathenoglobenemia. Organisms that belong to the
Organisms that belong to the second trophic level.second trophic level. Herbivores. Herbivores. PAN is a powerful lachrymator or t
PAN is a powerful lachrymator or t ear producer formed from unburnedear producer formed from unburned hydrocarbons, aldehydes, nitrogen oxides and oxygen. PAN stands for hydrocarbons, aldehydes, nitrogen oxides and oxygen. PAN stands for peroxyacetyl nitrate.
peroxyacetyl nitrate.
Part of the atmosphere where most of the photochemical reactions take Part of the atmosphere where most of the photochemical reactions take place.
place. Mesosphere. Mesosphere.
Particulates (< 1micrometer) remaining suspended in air indefinitely Particulates (< 1micrometer) remaining suspended in air indefinitely and transported by wind currents are called
and transported by wind currents are called aerosolsaerosols Problem Solving
Problem Solving
Process of converting nitrogen gas to ammonia is called
Process of converting nitrogen gas to ammonia is called nitrogennitrogen fixation.
fixation.
Process where decomposers return back the nitrogen to the soils t Process where decomposers return back the nitrogen to the soils t hroughhrough the remains and waste of plants and animals.
the remains and waste of plants and animals. Ammonification. Ammonification.
Process whereby coarse matter (suspended or floating) of a
Process whereby coarse matter (suspended or floating) of a certain sizecertain size can be strained out of flowing water with the aid of bars, fine wires or can be strained out of flowing water with the aid of bars, fine wires or rocks.
rocks. Screening.Screening.
Recyclable material labeled as no. 3 Recyclable material labeled as no. 3 PVC. PVC.
Removal of all settleable particles rendered settleable under the Removal of all settleable particles rendered settleable under the influence of gravity, basically the theory of gravity under the influence influence of gravity, basically the theory of gravity under the influence of which all particles heavier than water tend to settle down. of which all particles heavier than water tend to settle down. Sedimentation.
Sedimentation. Temporary hardness
Temporary hardness is a substance in water is removed by Lime Soda is a substance in water is removed by Lime Soda Process.
Process.
The alkalinity of wastewater is due to the presence of the following The alkalinity of wastewater is due to the presence of the following except
except dissolved COdissolved CO22..
The amount of chlorine available in water a
The amount of chlorine available in water a fter the disinfection is calledfter the disinfection is called residual chlorine.
residual chlorine.
The liquid produced when water percolates through any permeable The liquid produced when water percolates through any permeable material.
material. leachateleachate
The permissible color for domestic water supply in ppm is The permissible color for domestic water supply in ppm is 20.20.
The pH of a water sample was found to be 6.3. The bicarbonate was The pH of a water sample was found to be 6.3. The bicarbonate was measured to be 2.1x10
measured to be 2.1x10-3-3M. Calculate the total carbonate if pK M. Calculate the total carbonate if pK a1
a1 and pk and pk a2a2 are 3.3 and 10.33, respectively.
are 3.3 and 10.33, respectively. 2.8x102.8x10-3-3
The process of killing infective bacteria in water is called
The process of killing infective bacteria in water is called sterilization. sterilization. The process where more harmful substances are produced from less The process where more harmful substances are produced from less harmful ones.
harmful ones. Synergism.Synergism.
The red brownish color of water is due to the presence of dissolved The red brownish color of water is due to the presence of dissolved impurities of
impurities of iron and manganese.iron and manganese.
The resistance of water to the passage of light
The resistance of water to the passage of light through it is a measure ofthrough it is a measure of the
the turbidity.turbidity.
The total solids in water are due to the presence of
The total solids in water are due to the presence of suspended suspended andand dissolved solids.
dissolved solids.
These are accumulated solids
These are accumulated solids removed from separation equipment suchremoved from separation equipment such as settling tanks and clarifiers.
as settling tanks and clarifiers. sludge. sludge.
These are closed compartments that use gravitational force to extract These are closed compartments that use gravitational force to extract dust and mist and typically used only for larger particles.
dust and mist and typically used only for larger particles. SettlingSettling chamber
chamber
These organisms feed on the waste of the ecosystem.
These organisms feed on the waste of the ecosystem. Detritivores. Detritivores. These reddish brown oxides in concentrated form may produce an These reddish brown oxides in concentrated form may produce an abnormal accumulation of fluids in the
abnormal accumulation of fluids in the lungs.lungs. NO NO x x This provides the blueprint for action t
This provides the blueprint for action t owards sustainable developmentowards sustainable development Agenda 21
Agenda 21
Total uptake of chemicals by an organism from food items as well as via Total uptake of chemicals by an organism from food items as well as via mass transport of dissolved chemicals.
mass transport of dissolved chemicals. Bioaccumulation. Bioaccumulation.
Type of recycling that involves recovery of chemicals or energy from Type of recycling that involves recovery of chemicals or energy from post-consumer waste materials.
post-consumer waste materials. tertiarytertiary
Type of wastewater treatment that employs biological methods to Type of wastewater treatment that employs biological methods to remove fine suspended, colloidal and diss
remove fine suspended, colloidal and diss olved organics by biochemicalolved organics by biochemical oxidation.
oxidation. Secondary treatment.Secondary treatment.
Type of wastewater treatment that employs physical and chemical Type of wastewater treatment that employs physical and chemical treatment methods to remove or reduce a high percentage of suspend treatment methods to remove or reduce a high percentage of suspend solids and toxic materials.
solids and toxic materials. Primary treatment. Primary treatment.
Water treatment that destroys disease-causing bacteria, nuisance Water treatment that destroys disease-causing bacteria, nuisance bacteria,
bacteria, parasites parasites and and other other organisms organisms and and remove remove soluble soluble iron,iron, manganese and hydrogen sulfide from water.
manganese and hydrogen sulfide from water. Chlorination.Chlorination. What is the atmospheric condition when the lapse rate is >10 What is the atmospheric condition when the lapse rate is >10OOC/km.C/km. Superadiabatic.
Superadiabatic.
When a sample of water is added to a medium of agar and incubated at When a sample of water is added to a medium of agar and incubated at 37
37OOC for 24hours, colonies of bacteria formed are countered. This testC for 24hours, colonies of bacteria formed are countered. This test is called
is called Total Count Test.Total Count Test.
Which of the ff is NOT classified as heavy industry in the list of Which of the ff is NOT classified as heavy industry in the list of environmentally critical projects..
Which of the following is NOT a physical characteristic of wastewater. Which of the following is NOT a physical characteristic of wastewater. Hardness.
Hardness.
Which of the following is not use for the
Which of the following is not use for the disinfection of water.disinfection of water. SulfuricSulfuric acid.
acid.
Which of the following is not used as adsorbent material. Which of the following is not used as adsorbent material. Water.Water. Which of the following maybe used to measure the assimilative capacit Which of the following maybe used to measure the assimilative capacit yy of a stream.
4 kg of water is placed in an enclosed volume of 1m3 heated until 150C. 4 kg of water is placed in an enclosed volume of 1m3 heated until 150C. Mass vapor is
Mass vapor is 2.542 kg.2.542 kg.
A heat pump provides 75MJ/hr to a house. Compressors require 4kW of A heat pump provides 75MJ/hr to a house. Compressors require 4kW of energy. COP
energy. COP is 5.21is 5.21
A steel cast
A steel cast ing 40kg at 450C is quenched in 150kg oil. Entropy ising 40kg at 450C is quenched in 150kg oil. Entropy is 9.8kJ/kg.9.8kJ/kg.
Air undergoes isentropic compression from 14.7 psia, 68F to 180.6psia and Air undergoes isentropic compression from 14.7 psia, 68F to 180.6psia and 621.5F.
621.5F. -94.8Btu/lbm-94.8Btu/lbm
An ice-making machine operates cyclica
An ice-making machine operates cyclica lly between 0-25C. The work donelly between 0-25C. The work done to freeze 100kg water at 0C to ice is
to freeze 100kg water at 0C to ice is 733.94kcal.733.94kcal.
An ideal Otto engine operating at the end of compression (840F) and An ideal Otto engine operating at the end of compression (840F) and expansion (2540F) with compression ratio of 7.5. Efficiency is
expansion (2540F) with compression ratio of 7.5. Efficiency is 55.3%55.3% An Otto cycle compression ratio of 7.5 operates at 14.2psia and 85F. The An Otto cycle compression ratio of 7.5 operates at 14.2psia and 85F. The pressure and temperature at the end
Calculate the entropy of steam at 60psia with a quality 0.6. 1.16
From 80F and 6ft3, 10lb H2 changes to 150F and 10ft3. Entropy is 8.1Btu/R From above find volume of vapor 0.9985m3.
From above, heat rejected is 13.3Btu. From above, work done is 27Btu. From above, work done is -719btu/lb air From above, work input is 3.95hp.
How many TOR required to produce 10MT of ice at -10C to 22C i f losses are 15% of the chilling and freezing load. 17TOR
If 150 L of N2 gas expands adiabatically at 1 atm to final volume of 250 L. 0.49 atm
In a Carnot cycle operating on N2, heat supplied is 40Btu and expansion ratio is 15.6 at 60F. Efficiency is 67%.
In an isentropic compression, P1- 100 psia, P2- 200 psia, V1- 10in3 and y-1.4. Find V2- 6.1in3
Steam engine is operating at 220-35C and delivers 8hp and efficiency of 30%. What is the actual efficiency. 11.3%
Steam generated in a power plant at 8600kPa and 500C fed to a turbine. Exhaust at 10kPa is saturated liquid. The efficiency of Rankine cycle is 39.7%.
Steam is expanded from 700F and 200psia to 5psia in an 87% efficient turbine. Final enthalpy is 1105.23 Btu/lbm
The work polytropic compression pf air from 15psia, 1ft3 to 150 psia and 0.15 ft3 is 5150ft-lb.
The work required to compress a gas reversibly according to pV1.3 is 50000ft-lb. Change in internal energy is 48.2Btu
The work required to compress a gas reversibly according to pV1.3 is 50000ft-lb. Heat loss is -16.1 Btu
There are removed 500Btu/min of heat from 440R to 550R. if COP is ¾ of Carnot, heat rejected is 667Btu/min.
If 1lbm of steam at 14.7psia, 63% quality is heated isentropically, at what pressure. 2585 psia
experiment that 1.000 gram of M combines with an excess oxygen to form 2.019 grams of oxide. The element M is manganese
X
P
He
Al
24 1530 27 13 H H Be 2 1 1 1 9 4 ___
Be
8% composition HC C = 84.2% H = 15.8% . What is its empirical formula C 4 H.
54.45% carbon 9.09% hydrogen, 36.36% oxygen . What is the empirical formula. C 2 H 4O.
a 1-L vessel established equilibrium with the following reaction: 2SO2+ O2 = 2SO3 mol SO2 = 0.11 mol O2 = 0.05 mol SO3 = 0.12 another 1-L vessel is used and contains SO2 mass SO2 = 96g . How much O2 (in grams) must be added, if at equilibrium, one half of SO2 will be converted to SO3 13.34.
a compound containing only phosphorus and hydrogen was fully combusted mass yield P4O10 = 17.9g mass yield H2O = 4.80g. What is the empirical formula of the compound PH 2.
GENERAL CHEMISTRY
mass compound sample with C,H,O = 0.95g , when fully combusted in oxygen gives mass H2O = 0.518g . mass CO2 = 2.13g . What is the simplest or empirical formula. C 5 H 6 O2.
mass Fe3O4 = 23g, In the reaction of Fe3O4 with carbon to form carbon dioxide and iron, the number of moles of carbon required to convert Fe3O4 to product 0.2.
mass fraction solute = 35 ppm . What is the concentration of chloride ion in percent in a solution that contains chloride 3.5 E-3%.
mass mixture (Cu2O and CuO) = 1.000g mass Cu = 0.865. The mass of Cu2O in the original sample of the mixture must have been 0.742g. mass O2 = 10.0g . What is the theoretical yield of SO2 for the reaction of the given mass O2 with sufficient S for complete reaction. 20.0g.
Naturally occurring Ga is composed of 60% Ga-69 and 40% Ga-71 atomic mass Ga-69 = 68.911 atomic mass Ga-71 = 70.931. Calculate the average atomic mass of Ga 69.72amu.
roasting of 100g of copper ore yields 75.4g of 89.5% pure copper . If the ore is composed of Cu2S and CuS with 11% inert impurity, calculate the percentage of Cu2S in the ore . 62%.
wt % sand = 70, wt % water = 30 density pure quartz = 165 lb/ft3 . What is the density of the mud, the sand is practically pure quartz 110.4 lb/ft 3,
[HBr] = 0.1 V HBr = 50 m l [KOH]titrant = 0.1M V base = 49mL. Calculate the pH after the volume of base has been added to 50 ml of HBr 3.0 [HCl] = 0.0015M . What is the concentration of OH in water solution 6.7E-12M
[HCl] = 0.10M volume HCl = 50.0ml [NaOH] = 0.20M, volume NaOH = 100ml . What is the pH of the resulting solution 13
[HCN] = 0.100M Ka HCN = 7.2E-10 . What is the pH of a solution 5.1 [HF solution] = 0.1M % dissociation = 9.5%. Calculate the K a for HF 1.0E-3.
[hydronium ion] = 2E-3M . What is the pH the a solution 2.7 [Mg2+] = 0.001M Ksp Mg(OH)
2 = 1.2E-11 . Calculate the pH of a solution necessary to just begin the precipitation of Mg(OH)2 10 [NaOH] = 0.100M V NaOH = 180 ml [HAcetic] = 0.100, V acetic = 200 ml K a acetic acid = 1.8E-5 . What is the pH of a buffer prepared by adding NaOH to acetic acid 5.70
[NH3] = 0.0500M Kb NH3 = 1.8E-5 . What is the pH of a solution 11.0 [NH4Cl] = 0.256M [NH3] = 1.8E-5 . What is the pH of NH4Cl 4.92 A metal reacts with water with the evolution of hydrogen and formation of its hydroxide. mass metal = 1 g atom (the chloride of metal was found to contain 13.7% chlorine) volume OH solution = 1L [HCl]= 0.9091N volume HCl = 110ml. The volume of hydrogen gas liberated at STP 11.2. The atomic weight of the metal 224. Since the solution of the OH of the metal is normal, the valency of the metal is 1.
buffer pH= 4.0 Ka benzoic acid = 6.5E-5. Which of the following solutions results in a the given buffer 0.16M benzoate and 0.25M benzoic acid. C(s) + CO2 = CO(g) Kc = 1.6, equilibrium concentration of CO2 = 0.5M . What is the equilibrium concentration of CO. 0.89
H2 + I2 = HI Kc for HI equilibrium@425C = 54.5, [H2]0 = 0.00623M [I2]0 = 0.00414M [HI]0 = 0.0224M . Calculate the concentration of I2 in equilibrium 0.00267M.
Ka HCN = 7.2E-10 . What is the ratio of acid concentration to anion concentration needed to produce a buffer of pH 10.0 using HCN and NaCN. 0.14
mass acid = 1.243g volume = 31.72 cm3 of 0.1923N. What is the equivalent weight of an acid of standard base for neutralization. 204 mass CaCO3 = 1.0kg . The maximum number of kilograms of CaO produced on heating 0.56kg.
mass impure sample Na2CO3 = 1.2048g (is dissolved and allowed to react with a CaCl2 solution) mass of resulting precipitate CaCO3 = 1.0362g . Assuming that the impurities do not contribute to the weight of the precipitate, calculate the percent purity of the Na2CO3. C%
mass of impure ammonium aluminum sulfate = 759.08mg, the aluminum in the sample was precipitated as Al(OH)3 and ignited at 1100C to yield Al2O3mass Al2O3 = 387.953mg . Express the result of analysis in terms of %Al 27%.
mass of KHP = 1.431g necessary in standardizing a solution of NaOH, mass alkali = 25.5ml mass acidrun back = 8.25ml (1ml=10.75 NaOH). What is the molarity of the NaOH solution 0.2598.
mass sample (containing Al(NO3)3, AlCl3, and inert) = 1.7483g (divided into two equal portions) Case 1: portion [AgNO3]titrant= 0.1M V AgNO3 = 50mL excess was titrated back with 28.89ml of 0.1002 M KSCN for titration Case 2: portion 2, [NaOH]titrant = 0.1193M V NaOH = 26.02 ml to completely precipitate as Al(OH)3 . Calculate the % AlCl3in the sample 10.70%.
mass sample (Na2CO3, NaHCO3,inert) = 1.179g, titrated acid= 0.1N, HCl volume acid = 24ml, indicator = phenolphthalein . Another duplicate sample was titrated with HCl; using methyl red as indicator. It required 50.25ml of the acid for color change. What is the % NaHCO3 in the sample. 18.7.
mass sample = 253.02mg containing NaBr and KBr was dissolved in water and treated with AgNO3 mass precipitate = 429.85mg. Calculate the %NBr in a sample 49%.
mass sample crude ammonium salt = 1.00g (treated with hot KOH solution) [acid] = 0.5N V acid= 50mL [NaOH] = 0.2N, 3.12 mL for neutralization . Calculate the %NH3 in the sample 41.25%
mass sample mixture (NaOH, Na2CO3, inert impurity) = 1.2g [HCl]titer = 0.5M indicator = phenolphthalein . the solution turns colorless after the addition of 30ml of the acid as a required for the color change to pink. Methyl orange is then added and 5ml more of the acid are needed to color change. What is the % Na2CO3in the sample. 22.08
mass sample of impure AlCl3 = 1.500g was dissolved in water and treated with AgNO3using Mohr method [AgNO3]titrant= 0.1000M V AgNO3= 45.32ml . Determine its purity AlCl3 (133.33 g/mol) 13.43%. mass vinegar = 3g titrated acid = 0.115N KOH, volume acid = 20.50ml indicator = phenolphthalein. What is the percentage of the total acid expressed as acetic acid in a sample of vinegar for an end point with the given indicator 6.72%.
mole AgCN = 0.0010 volume = 1L K HCN = 4E-10, Ksp AgCN = 1.6E-14 . What (H+) is needed to dissolve completely AgCN 0.025M
n ammonia = 0.25 mol K b = 1.8E-5 . What is the pH of a solution prepared from ammonia dissolved in sufficient water to make 1L
solution 11.33.
pH buffer = 5 . What is the ratio of the concentration of acetic acid to sodium acetate 0.56
solubility barium sulphate = 0.0091g/L @ 25C MW barium sulphate = 233g/mol . What is the solubility product constant of barium sulphate. 1.523E-9.
sp.gr HCl solution (23.81%wt. HCl)= 1.12. How many grams of HCl are present in each milliliter solution. 0.27
volume of 0.1N NaOH= 10ml volume of 0.1N HAc= 25ml Calculate the pH of the solution 4.57.
What are the percentages by mass of each element in CaCl2. 36.1%Ca and 63.9% Cl.
mass alkane = 2.2g mass bromine = 3.2g . The molecular formula of A C 8 H 16,
moles alkane = I mole, moles water = 7 moles . an alkane reacts with excess O2 to give water. The alkane could be hexane.
moles alkane = I mole, moles water = 7 moles . moles of CO2 generated from the same alkane 6.
saponification number of triglyceride = 200 . Average MW of triglyceride 840.
Ammonium iodide dissociates reversibly to ammonia and hydrogen iodide. NH4(s)↔ NH3(g) + HI(g) K p @ 400C = 0.215. If 150g of ammonium iodide is placed into a 3-L vessel and heated to 400C, calculate the partial pressure of ammonia when equilibrium is reached. 0.46 atm.
angstrom = 3.92 face-centered cubic crystal density = 21.5 g/ml . What is its atomic weight 195.
At volume vessel 1 = 1L established equilibrium with the rxn: 2SO2 + O2 = 2 SO3 mol SO2= 0.11 mol O2 = 0.05 mol SO3 = 0.12 @volume vessel 2 = 1L mass SO2 = 96g initially. How much O2 (in grams) must be added, if at equilibrium, one half of SO2 will be converted to SO3 13.34.
Calculate the root mean square speed of a helium atom at 298K 1363 m/s charge = 8.5E3coulombs . How many grams of iron (Fe) could be deposited from a solution of FeCl2 2.46.
D tube = 3mm Length tube = 78.74 inches, Pressure head = 6.5 N/cm2, volume fluid = 0.04 m3 passes through the tube every 1 minute. What is the viscosity of the fluid. 0.097cP.
E = 75,000 cal/mol (pyrolysis of ethane). How much faster is the decomposition at 650C than at 500C. 2795 times faster.
electrical current = 10 amperes . What is the mass of aluminum produced in 1 hour in the electrolysis of molten aluminum sulfate 3.36g. t1/2of radioactive isotope C-14 = 5720 years mass of sample carbon = 1.00g undergoes 15 disintegrations per minute per gram. How old is a 10.0g sample for which the rate i s 0.91 disintegrations per minute per gram 4120 years.
frequency: 5.11E+11 Hz . What is the wavelength of radiation 5.87E-4 m. heat of combustion methanol = -173.7 kcal/mol @18C, heat of combustion CO = -67.6 kcal/mol @ 18Cn heat of formation of H2O(l) = -68.4 kcl/mol . Find the heat of reaction at 18C for CO(g) + 2H2(g) = CH3OH(l) -30.7 kcal.
mass calcium nitrate = 11.3g mass water = 115g . What is the freezing point of a solution -3.34C
mass defect for the triton (tritium nucleus) = 0.00910amu. Calculate the binding energy per nucleon 2.825 MeV.
mass Fe(s) = 1.67g t = 1.00 hour . What current would be necessary to deposit Fe(s) from a solution of Fe3+ (aq) 2.40A.
mass gas density bulbevacuated/empty = 29.3215g mass bulb with CO2 gas @40C, 1 atm = 30.0079g mass bulb with CO and CO2 at same T&P = 29.9332g . Determine the % of CO in the mixture 29.9.
mass hydrogen= 0.504g time the current is liberated= 2 hours. How many grams of copper can be liberated by t he same current flowing for the same time in a copper sulfate solution. 15.9.
mass isotope = 1 g t1/2 isotope = 15 hours . The half-life of 0.50g sample 15 hours.
mass isotope = 1g t1/2 = 15 hours . The half life of 0.50g sample 7.5 hours.
mass metal = 400g heated to =96.5C mass H2O at calorimeter = 2000g @20C Tf = 21.5C . What is the specific heat of the metal in cal/g.C 0.10 mass N2O4= 1.588g total pressure = 1.0133 bar, volume glass vessel @ 25C = 500 cm3 . What is the value of Kp. 0.143 bar.
ORGANIC CHEMISTRY
mass of flask evacuated = 134.567g pressure gas = 735torr @ 310C, mass of flask after filling with gas @ given P and T = 137.456g mass of flask filled with water@31C = 1067.9g . Assuming ideal gas equation applies, calculate the molar mass of the unknown gas 79.7.
mole Cl2 = 1.00 mol V = 1.00L T = 200K, a=0.493L2-atm/mol2 b=0.5622 L/mol . What is the pressure calculated by van der waals
equation 31.0 atm.
moles of electrons = 3.00 potential = 1.74 V, What is the electrical work done 5.07E5J.
PCl3(g) heat PCl3(g) + Cl2(g), dissociates, T = 250C P = 1 atm density = 4.4g/L at equilibrium . The fraction of PCl5 dissociated is 0.103. T = 25C . The difference between the heat of combustion of methane at constant pressure and at constant volume when liquid water forms -1257.4 cal.
T = 27C . The difference between the heat of combustion of methane at constant pressure and at constant volume at the given temperature when the liquid water forms. -1192.2 cal.
T1 = 20C T2 = 100C electric current = 10A, voltage = 10V t = 10 hours. Calculate the mass of water in grams that could be heated 10,755. viscosity coeff of gaseous Cl = 147.0 micropoise @ 20C. Find the molecular diameter of the chlorine molecule. 4.22E-8cm.
volume 1 methane= 200ml Temperature= -42C, volume 2 methane= 100ml . Find the final temperature 74.
volume gas mixture (N2 and CO2) = 10.0 L (with 3.00g N2), PT = 0.750atm\ T = 273K . What is the partial pressure of CO2(g) in the mixture. 0.510 atm.
VP pure benzene @ 25C = 0.1252 atm ma ss unknown HC= 6.4g mass, pure benzene (MW=78) = 78g VP benzene in solution = 0.1192 atm .
What is the molar weight of the unknown solid. 128.
VP pure ethyl alcohol @ 30C = 71.2 torr VP pure carbon tetrachloride = 121.6 torr mass ethyl alcohol = 20g mass carbon tetrachloride = 60g . Calculate the pressure above a solution assuming ideal behavior 95.0 torr.
Z = 2.50 @ 65.0 atm n gas = 2.00 moles, V gas = 1.00L P = 65.0 atm. What is the temperature of this gas 158K.
a closed gaseous system undergoes a reversible process Qrejected = 25 BTU V1 = 5ft3 V2 = 2ft3 P = (constant) 50psia. Find delta U 2.76 BTU. heat content of 70% NaOH liquor @ 160F = 325 btu/lb is diluted with 20% NaOH liquor @ 80F heat content 20% NaOH liquor = 40 btu/lb heat content final solution, 40% NaOH = 94 btu/lb . For every 100lb product, how much heat must be removed to maintain a final product
temperature of 100F. 6000 btu.
heat engine absorbs heat from the combustion of gasoline @ T=2200C, sp.gr of gasoline = 0.8 heat combustion = 11,200 calories per gram T = 1200C, engine rejects heat . The maximum work in calories that can be obtained from the combustion of 1L gasoline 3.26E6 cal.
heat of combustion benzoic acid = -770.9 kcal/mol (measured in bomb calorimeter) @ 25C . Find the heat of combustion of benzoic acid in kcal/mol at 25C in a stream of oxygen assuming complete condensation of water vapor to liquid -771.2.
helium is compressed isothermally P= 14.7 psia, T = 68 F compression ratio = 4 . Determine the change in entropy of the gas in BTU/lbF -0.689.
mass Cu = 5lb T = 200F mass water = 10lbm . Copper is submerged in water and after a period of time, equilibrium is established. What is the entropy change of the system. 0.0167 BTU/R.
mass ice cubes = 5 lbs (manufacture from water initially at 32F) T, surrounding air = 80F latent heat of fusion of water = 143.4 btu/lb. The minimum work 70.0 btu.
mass of ice = 100g. T1 = 0C (ice) T2 = 100 C @ 1 atm (steam) . Calculate the change in entropy in converting ice to steam 205.28eu.
mass of oxygen gas = 8 grams @ 27C, 10 atm and expands adiabatically and reversibly Pfinal = 1.0 atm . The work done in the process -752 J. moles of ideal gas= 3 @ P = 1 atm @ T = 20C, heated at constant pressure Tfinal = 80C Cv = 7.50 + 3.2E-2T, cal/mol.K. The change in
internal energy of the process is 3210.50 cal.
P1 = 1 bar (initial condition air is compressed) @ 25C, P2 = 5 bars @ 25C . Assume air is ideal gas, calculate the work done in J/mol 3990. Calculate the heat required in J/mol -3990.
P1 = 200kPa P2 = 150 kPa . For an ideal gas, what is the specific molar entropy change during an isothermal process. 2.39 J/mol-K.
Psat steam= 350 kPa mixed with water at 15C Thot water = (produced from mixing) 80C rate mixing = 4 kg/s internal diameter = 50mm (inlet and outlet lines to the mi xing device) . At what rate must steam be supplied 0.41 kg/s.
Q = 1055kJ T = 427C (heat engine absorbs heat), T = 38C (heat engine rejects heat) . The work done in kJ by the engine if its efficiency is 50% of the carnot engine is closest to 496.6kJ.
Qabsorb= 1055kJ @ T =427C, Treject= 38C . The work done in kJ by the engine if its efficiency is 50% of the Carnot efficiency is closest to 293.3 kJ.
refrigerator capacity = 3140 watts input rating = 735 watts. The coefficient of performance of the refrigerator is 4.27.
T = 100C (water evaporates) @ 1 at m . Calculate the work done by the system in which 1 kmole of water evaporated 3060 kJ.
Tsteam = 212F mass water = 400lb, Twater = 70F heat losses = 2000 Btu . Find the amount of steam to make the TF of water to be 212F 60.6 lb. two carnot engines are operating in series. T1 (absorbs) = 1,111K T2 (rejects), the second engine receives the heat at the intermediate temperature T and rejects it to Treservoir Treservoir = 300K . Calculate T if the efficiencies of the two engines are equal. 577K Required 2: From the data above, calculate T i f the work done by the two engines are equal. 705K.
VP acetic acid @ 90C = 293 mmHg VP acetic acid @ 100C = 417 mmHg . Calculate the normal boiling point of acetic acid 391.3K.
A fixture containing an ordinary incandescent light bulb is connected to a dimmer switch. Temperature of the tungsten filament inside the bulb increases from 1300K- 2600K. Total Power radiated by the bulb. Increase 16x
A heat exchanger is required to c ool 20kg/s of water. T= 360K to 340K. m=25kg/s. Tentering water=300K. Overall coefficient of heat transfer= 2 kW/m2-K.Calculate the surface area required in a counter concentric tube exchanger. 20m2
A method where engineers assure the existence of an exchanger and make calculations to determine if the exchanger would handle the process. Rate an exchanger
A popular type of heat exchanger for cooling large quantities of fluid. Low thermal conductivity
A reaction mixture,Cp= 2.85 kJ/kg-K, flowing at a rate= 7260kg/hr. to be cooled from 377.6K to 344.3K. Tcooling water= 288.8K, flow rate= 4536kg/hr. OHTC= 653 W/m2-K.Calculate the outlet water temperature. 51.95°C
A single 4-in steel pipe, OD = 4.5 inch, outer surface temperature= 300°F. The horizontal pipe in a large room with ambient temperature= 78°F at standard barometer. The heat total (natural convection and radiation) for 25ft of length in Btu/hr. 21100
Air Tin=75°C, Tout= 225°F. Hot gas: Tout= 265°F. LMTD= 140°F. Find the temperature of the hot gas entering. 325°F
An economizer receives hot gas (Cp=0.27 BTU/lb-°R) and water in the ratio of 1.5 lb gas per lb water. Tgas in= 850°C. Tgas out= 355°F. Twater in= 120°F. Find the exit temperature of the water if the flow is parallel. 320°F
An insulator should have. Low thermal conductivity
Benzene at 100°F and 1 atm flows at 100ft3/min in a smooth 1” ID tube. The heat transfer coefficient for the system in BTU/ sec-ft2-°F
Calculate the inside area of the coil in ft2. 2.664 4. Calculate the gpm of water cooled. 0.380
Composite wall at 2000°F. Outside ambient temperature at 70°F. Three layers composite wall, 12, 12 and 10 inches. Thermal conductivities: 0.4,0.2 and 0.1BTU/hr-ft-°F. Inside heat transfer is negligible. Outside air film heat transfer coefficient is 2BTU/hr-ft2-°F. Heat loss through the composite wall in BTU/hr-ft2 is. 118.2
Composite wall composed of 2” cork on the inside, 6” concrete and 3” wool on the outside. Thermal conductivities= 0.025,0.8 and 0.065 BTU/ hr-ft-°F. Inside surface temperature= 40°F. outside t emp=78°F. What is the heat flux through the wall in BTU/hr-ft2. 3.41
Determine the rate of conduction of copper rod. Diameter= 2mm, Length= 150 mm. Temperatures: 300°C at one end and 20°C at the other end. Ave. thermal conductivity= 1.36E6 J/s-m-K. 7890W
Determine the temperature (in °F) at the junction between the firebrick and the insulating brick. 1533
Determine the temperature (in °F) at the junction between the insulating brick and common brick. 328 6.Calculate the heat loss per linear foot from 2in nominal pipe (2.375 in outside diam eter). Covered with 1 inch of an insulating material. average thermal conductivity= 0.0375 BTU/hr-ft-°F. Temperatures of the insulation= 390°F and 80°F. 120BTU/hr-ft
Dittus-Boelter equation for the determination of heat transfer coeff. is valid. For fluids in turbulent flow
Film and drop are the terms associated with. Condensation
Find the thermal conductivity of a 0.5m thick material with an area of 5m2 and a temperature difference of 10K if the heat transmitted during 2hrs of test is 2000kJ. 2.78 W/m-K
Flat wall with 6inch layer firebrick( k=0.95BTU/ hr-ft-°F), 4inches insulating brick (k=0.14), and 4inches common brick (k=0.8). Firewall temperature= 1800°F, outer surface temperature= 120°F. The heat loss through the wall in BTU/hr-ft2. 506
Heat loss (W/m2) by radiation & convection from an unlagged horizontal steam pipe, 50mm, od. At 377K. Air at 283K. 1587
Heat transfer area for a natural convection. Horizontal pipe diameter= 0.15m. Surface temperature of 400K to air at 294K. 6.81 W/m2-K Convection coefficient of heat transfer of nickel wire(0.035 in diameter at 1700°F) to air is equal t o 6 BTU/ hr-ft2-°F. How much heat is lost by 1ft of wire inside an oxidized copper container, the air and container being 160°F. 85BTU/hr
Hollow metal sphere. Inside wall temperature= 300°F. Internal diameter= 6 inches and 2inch thick. Outer surface= 212°F. Thermal conductivity of metal= 8BTU/hr-ft-°F. What is the heat loss from the sphere. 5529BTU/hr
Hollow sphere. Outside radius= 1m made up of polystyrene foam. Thickness= 1cm. the inner surface is 5.20°C hotter than the outside surface. Thermal conductivity of polystyrene foam= 0.033 W/m-°C. The power produced by the heat source. 214 W
How much part of the light is absorbed by the body that t ransmits and reflects 80% and 10% respectively. 10%
If a man touches two metals which were kept together at room temperature, why would one metal feel colder than the other. One has higher thermal conductivity
In a heat transfer equipment, dirt or scale may be accounted by introducing a resistance called. Fouling factors
In a steady state heat t ransfer through a series of materials with varying resistance, the heat transfer. Is constant throughout the series of materials
In convection heat transfer, the mechanism of heat transfer where the fluid moves due to the decrease in its density caused by increased in temperature. Natural convection
In heat exchanger the area of heat transfer is calculated from. The total lateral area of the tubes
LMTD. 230°F
Metal rod= 10cm long, diameter= 2cm. One end is in contact with steam at 100°C while the other end is in contact with ice at 0°C. 320g of ice melted after 20 mins. The thermal conductivity is. 283.6 W/m-K Methyl alcohol flowing in the inner pipe of a double pipe exchanger is cooled with water flowing in the jacket. Inner pipe= 1-inch(25mm), Sched 40 steel pipe. Steel thermal conductivity= 26 BTU/hr-ft-°F(45 W/m- °C). hi = 180 BTU/hr-ft2-°F(1020 W/m2-°C), hdi= 1000 BTU/ hr-ft2-°F (5680 W/m2-°C), ho= 600 BTU/ hr-ft2-°F(3402 W/m2-°C), hdo= 500 BTU/hr-ft2-°F(2840 W/m2-°C). What is the overall heat transfer coefficient based on the outside area of the inner pipe in BTU/hr-ft2-°F). 80.9
Pipe diameter= 50mm with circular section with walls 3mm thick covered with two concentric layers of lagging. Inner layer thickness= 25mm with thermal conductivity= 0.08 W/m-K. outer layer thickness= 40mm with thermal conductivity= 0.04 W/m-K. What is the rate of heat per meter length of pipe. Ti= 550K, To surface temp= 330K. 62.7W/m
Ratio of the molecular diffusivity and momentum in liquid is known as the. Prandtl no.
Refractory material… Emissivity of 0.40 at 1500K and 0.43 at1420K. Temperature of 1420K exposed to black furnace walls at 1500K. The rate of gain of heat by radiation per unit area in Kw/m2. 24.3
Stack gases leave a boiler, pa ss through a square steel duct 3ft by 3ft and 16ft long. And enter a masonry chimney. Estimate the heat transfer coefficient (in BTU/hr-ft2-°F) in the duct if the gases are at 900°F and 1 atm. Consider the stack gases to have the same properties as air. The gas velocity is 50ft/sec.
Steam pipe. Outside diameter= 2inches. Inside surface temperature= 350°F. pipe coating material= 2inch thick. Thermal conductivity: k= 0.5 + 5E-4T in °F. k in BTU/hr-ft-°F. Outside surface coating= 100°F. Calculate the heat loss per foot of pipe length. 877 BTU/hr
Surface temperature is. 129.1°F
The area assuming it’s co-current. 6.46m2 The area assuming it’s counter current. 5.43m2
The inside and outside surfaces of window glass are 20°C and -5°C. Glass: 100cm by 50cm in size and 1.5cm thick. Thermal conductivity= 0.78 W/m-K. Heat loss through the glass at 2hrs. 1.30kWh
The main trunk duct of an air conditioning system is rectangular in cross-section(16in x 30in) and has air at 15psia and 40°F flowing through it with velocity of 1400 fpm. Find hi in BTU/ hr-ft2-°F. 4.50 The mode of heat transfer that can take place in a vacuum. Radiation The overall conductance for a composite material in series is equal to the. Inverse of the total resistance
The total heat loss by radiation and convection from unlagged horizontal steram pipe of 50mm diameter at 415K at air= 290K. 384W/m
The transfer of heat through and by means of matter. Conduction The view factor F21 of a sphere(1) of diameter D inside a cubical box(2) of length L which is equal to D is. 0.524
Two very large walls at constant temperatures (800°F and 1000°F). Emissivities: 0.6 & 0.8. Net exchange heat in BTU/hr-ft2. 1825
Water cooler uses 50lb/hr of melting ice to cool running water from 80°F to 42°F. Ui= 110 BTU/hr-ft2-°F. Find the LMTD. 24.24 °F
What is the reason why Styrofoam is a good insulating material. Because it contains many tiny air pockets of air
2000kg/h of a mixture consisting of 60%wt benzene and 40%wt toluene is to be separated in a distillation column. The distillate is to contain 98%wt benzene and 95% of the feed benzene is to be recovered as distillate. what is the flow rate of the distillate. 1163kg/h
41.78oBe is equivalent to 42.12oAPI.
A contract was made between a buyer and a paper manufacturer for paper containing 5% moisture at P450/ton on specification that price
adjustment will be made if the quality is different. How much should the buyer pay for 1 ton of paper with 8% moisture content. Freight cost is P45/ton. P434.16
A dehumidifier sprays 50lb/min of cold water into a stream of air. 100lb/min of wet air enters the dehumidifying chamber. The absolute humidity of the entering air is 0.05lbwater/lb d.a. What is the total of the liquid water leaving the chamber per minute. 53.81
A mixing tank mixes two inlet streams containing salt. The salt concentration in stream 1 is 5% by weight and in stream 2 15% by
