QUESTION BANK
CHEMISTRY
Gujarat Secondary and Higher
Secondary Education Board,
Gandhinagar
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Contribution
1 Dr. Hasmukh Adhiya (IAS) Principal Secretary , Education Department Gandhinagar 2 Shri R. R. Varsani (IAS) Chairman , G.S&H.S.E. Bord, Gandhinagar
3 Shri H. K. Patel (G.A.S) Dy. Chairman, G.S&H.S.E. Bord, Gandhinagar 4 Shri M. I. Joshi (G.E.S) Secretary , G.S&H.S.E. Bord, Gandhinagar
Coordination
1 Shri B. K. Patel O.S.D., G.S&H.S.E. Bord, Gandhinagar
2 Shri D. A.Vankar Assistant Secretary (Retd.), G.S&H.S.E. Bord, Gandhinagar 5 Shri M. P. Parmar Assistant Secretary, G.S&H.S.E. Bord, Gandhinagar
Expert Teachers
1. Shri C. I. Patel (Convenor) Shri Vidyanagar High School, Ahmedabad 2. Shri S. B. Gor (Co-Convenor) Ghyanda Girls High School, Ahmedabad 3. Shri A. I. Patel Navchetan High School, Ahmedabad 4. Shri V. R. Patel
5. Shri B. R. Patel Muktjeevan Vidhyalaya, Ahmedabad 6. Shri K. K. Purohit M. K. Higher Sec. School, Ahmedabad 7. Shri M. B. Patel New Vidhyavihar for Girls, Ahmedabad 8. Shri B. A. Nayak Swaminarayan High School, Ahmedabad 9. Shri H. M. Patel
10. Shri S. B. Suthar R.P.T.P. Science School, Vallabh Vidhyanagar 11. Shri R. N. Patel R.P.T.P. Science School, Vallabh Vidhyanagar 12. Shri N. N. Shah Best High School, Ahmedabad
13. Shri J. Y. Mehta 14. Shri I. B. Amlani 15. Smt. M. N. Shethiya 16. Smt. H. N. Nayak
17. Smt. P. S. Thakar R.P.T.P. Science School, Vallabh Vidhyanagar 18. Shri G. S. Patel
19. Shri M. L. Sharma 20. Shri H. K. Patel
P R E FA C E
Uptil now , the Students had to appear in various entrance examinations for engineering and medical courses after std-12. The burden of examinations on the side of the students was increasing day-by-day. For alleviating this difficulty faced by the students, from the current year, the Ministry of Human Resource Development , Government of India, has Introduced a system of examination covering whole country. For entrance to engineering colleges, JEE(Main) and JEE(Advanced) examinations will be held by the CBSE. The Government of Gujarat has except the new system and has decided to follow the examinations to be held by the CBSE.
Necessary information pertaining to the proposed JEE (Main) and JEE(Advanced) examination is available on CBSE website www.cbse.nic.in and it is requested that the parents and students may visit this website and obtain latest information – guidance and prepare for the proposed examination accordingly. The detailed information about the syllabus of the proposed examination, method of entrances in the examination /centers/ places/cities of the examinations etc. is available on the said website. You are requested to go through the same carefully. The information booklet in Gujarati for JEE( Main) examination booklet has been brought out by the Board for Students and the beneficieries and a copy of this has been already sent to all the schools of the state. You are requested to take full advantage of the same also However, it is very essential to visit the above CBSE website from time to time for the latest information – guidance . An humble effort has been made by the Gujarat secondary and Higher Secondary Education Boards, Gandhinagar for JEE and NEET examinations considering the demands of the students and parents , a question bank has been prepared by the expert teachers of the science stream in the state. The MCQ type Objective questions in this Question Bank will provide best guidance to the students and we hope that it will be helpful for the JEE and NEET examinations.
It may please be noted that this “Question Bank” is only for the guidance of the Students and it is not a necessary to believe that questions given in it will be asked in the examinations. This Question Bank is only for the guidance and practice of the Students. We hope that this Question Bank will be useful and guiding for the Students appearing in JEE and NEET entrance examinations. We have taken all the care to make this Question Bank error free, however, if any error or omission is found, you are requested to refer to the text – books.
M.I. Joshi R.R. Varsani (IAS)
I N D E X
IV
UNIT 1 SOME BASIC CONCEPTS IN CHEMISTRY 1
UNIT 2 STATES OF MATTER 20
UNIT 3 STRUCTURE OF ATOM 44
UNIT 4 CHEMICAL BONDING AND ATOMIC STRUCTURE 79
UNIT 5 CHEMICAL THERMODYNAMICS 96
UNIT 6 SOLUTIONS 120
UNIT 7 EQUILIBRIUM 151
UNIT 8 REDOX REACTIONS & ELECTROCHEMISTY 183
UNIT 9 CHEMICAL KINETICS 207
UNIT 10 SURFACE CHEMISTRY 230
UNIT 11 CLASSIFICATION OF ELEMENTS AND PERIODICITY
IN PROPERTIES 241
UNIT 12 GENERAL PRINCIPLES AND PROCESSES OF
ISOLATION OF METALS 263
UNIT 13 HYDROGEN 283
1
Important Points
[A] Important formulae :
1. . mass No of moles Molar mass 2. . 22.4 Volume at STP No of moles of gas 3. 23 . . 6.022 10 No of Particles No of moles of Particles 4. No of moles of solute. Molarity Vol L ( ) 5.
M.W.of salt Eq. wt. of a salt =
Total + ve charge of metal ion
6. Eq wt of element. . Atomic Weight
Valency 7. . . m a n b Avg at mass m n
where, a + b are atomic masses and m + n are precentage.
8. % of element in compound = ( ) 100
. .
n at mass of element
M W of compound
where, n= No. of atoms of that element 9. 1000 . . ( ) w Molarity M W V ml 10. 1000 . . ( ) w Normality E W V ml 11. 1000 ( ) w Molality MW Wo g Wo = Weight of solvent 12. ( ) n Mole fraction X n N 13. % 100 W W W W Wo 14. 6 ( ) 10 ( )
weight vol of solute ppm
weight vol of solution
2 15. Molecalar weight = 2 V.D. 16. 2 . . Wt of metal 1.008 Eq wt of metal wt of H displaced 17. 2 . 11200 . ( ) Wt of metal Eq wt of metal Vol of H displaced at STP mL 18. Eq wt of metal. Wt of metal. 35.5 Wt of Chlorine combined 19. 2 . 11200 . ( ) Wt of metal Eq wt of metal Vol of Cl combined at STP mL 20. . 8 . Wt of metal Eq wt of metal Wt of oxygen combined 21. 2 . 5600 . ( ) Wt of metal Eq wt of metal Vol of O displaced at STP mL 22. %W W density 10 Molority Molecular weight 23. M V1 1M V2 2 (Molarity equation) 24. N V1 1 N V2 2 (Normality equation) 25. Molecular weight n
Empirical formula Weight
26. 0 9(0 ) 32 5 F C 27. 0 273.15 K C 28. 3 3 1L1dm , 1mL1cm [B] Important Facts :
1. Antoine Lavoisier - Law of conservation of mass 2. Joseph proust - Law of definite proportions 3. John Dalton - Law of Multiple proportions 4. Richter - Law of combining weights. 5. Gay Lussac - Law of combining Volumes. 6. 1 amu = 1.6605 x 10-24 gram
7. 12 23
1.9926 10
Mass of C atom gram
8. 23
( A) 6.022 10
Avogadro number N
9. AZT = Azido thymidine,drug used for aids victims.
10. The limiting reagent is the reagent that is entirely consumed when a reaction goes to completion. Its amount limits the amount of the product formed.
3
[c] Precision and Accuracy.
The term precision refers for the closeness of the set of values obtained form identical measurements of a quantity.
Accuracy refers to the closeness of a single measurement to its true value.
Let us take an example to illustrute. this. Three students were asked to determine the mass of a piece of metal where mass is known to be 0.520g. Data obtained by each Student are recorded in table below
mesurements in g.
1 2 3 Average Student A 0.521 0.515 .0509 0.515 Student B 0.516 0.515 .0514 0.515 Student C 0.521 0.500 .0520 0.520
The data for student A are neither, precise nor accurate. The data for student B are precise but not accurate. The data for student C are both precise and accurate.
M.C.Q.
1. Identify the wrong statement in the follwing (AIEEE 2008).(a) CFCs are responsible for ozone layer depletion. (b) Greenhouse effect is responsible for global warming.
(c) Ozone layer does not permit I.R. radiation from the sun to reach the earth. (d) Acid rain is mostly because of oxides of ‘N’ and ‘S’.
2. In the reaction
3
( ) ( )
( ) ( ) 2( )
2Als 6HClaq Al aq 6Claq 3H g (AIEEE 2007) (a) 6LHC1(aq) is consumed for every 3L, H2( )g produced.
(b) 33.6L H2( )g is produced regardless of temperature and pressure for every mole of Al that reacts.
(c) 67.2L
( ) 2g
H at STP, is produced for every mole Al that reacts. (d) 11.2L
( ) 2g
H at STP, is produced for every mole HC1(aq) consumed.
3. Consider a titration of potassium dichromate solution with acidified Mohr’s salt solution using diphenyl amine as indicator. The number of moles of Mohr’s salt required per mole of dichromate is (IIT JEE 2007)
(a) 3 (b) 4 (c) 5 (d) 6
4. Which has maximum number of atoms ? (IIT JEE 2003)
(a) 24g of C (12) (b) 56g of Fe(56) (c) 27g of Al (27) (d)108g of Ag (108)
5. What volume of hydrogen gas at 273K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) form the reduction of boron trichloride by hydrogen (AIEEE 2003)
(a) 89.6L(b) 67.2L (c) 44.8L (d) 22.4L
6. In an organic compound of molar mass 108g/mol, C,H and N atoms are present in 9:1:3.5 by weight Molecular formula can be (AIEEE 2002)
(a) C H N6 8 2 (b) C H N6 10
4
7. Number of atoms in 560 g of Fe (atomic mass = 56) is (AIEEE 2002) (a) twice that of 70 g N. (b) half that of 20 g H
(c) both (a) and (b) (d) None of these
8. In the standardization of Na S O using 2 2 3 K Cr O by iodometry, the equivalent weight of 2 2 7 K Cr O is2 2 7
(IIT JEE 2001) (a) 2 Molar mass (b) 6 Molar mass (c) 3 Molar mass
(d) same as molar mass
9. Mixture X=0.02 mole of [Co(NH3)5SO4]Br and 0.02 mole of[Co(NH3)5Br]SO4 was prepared in 2L of Solution
3
1L of mixture X excess AgNO Y
2
1L of mixture X excess BaCl Z
Number of mole of Y and Z are (IIT JEE 2003) (a) 0.01, 0.01 (b) 0.02, 0.01
(c) 0.01,0.02 (d) 0.02, 0.02
10. How many moles of electron weight one kilogram ? (IIT JEE 2002)
(a) 23 6.023 10 (b) 1 1031 9.108 (c) 6.023 1054 9.108 (d) 8 1 10 9.108 6.023
11. An Oxide of metal contains 60% of the metal. What will be the equivalent weight of the metal ? (a) 12 (b) 40 (c) 24 (d) 48
12. A container is filled with 2L of water. What will be the volume of water in m3?
(a) 3
2 10 (b) 3
1 10 (c) 3
2 10 (d) 3
1 10
13. The mass of carbon -12 atom considered in the definition of a mole is (a) 0.012Kg (b) 0.12g (c) 120 mg (d) None of these 14. The drug which is used for treating AIDS victims is
(a) Azidothymidine (b) Cis- platin (c) Taxol (d) All of these
15. Chose the incorrect statement .
(a) The constituents of a compound cannot be separated into simpler substances by physical meth-ods.
(b) An element is consists of only one type of particles and these particles may be atoms or molecules. (c) The properties of a compound are same as its constituent elements.
5
16. Which of the following is a pair of physical and chemical property respectively of a substance ? (a) acidity & combustibility (b) colour & density
(c) basicity & colour (d) density & acidity.
17. What is the symbol of S.I. unit for the amount of substance ? (a) NA (b) n (c) mole (d) mol
18. What is the symbol of a multiple ‘109’ ?
(a) G (b) E (c) n (d) Z 19. Find the correct relation.
(a) 9( ) 32 5 o o F C (b) 5 ( 32) 9 o o C F
(c) Both & (a) and (b) (d) Neither (a) nor (b)
20. In chemistry a number is represented in the form N 10n . This method of expressing the number is
called scientific notation. What is the value of ‘N’ here. (a) 1 to 10 (b) 0.1 to 9.99
(c) 10 to 100 (d) Any value can be taken 21. What is the correct scientific notation for 0.00016 ?
(a) 4
1.6 10 (b) 5
16 10
(c) 3
0.16 10 (d)cannot be determined. 22. How many significant digits are there in 0.25 ?
(a) 1 (b) 2 (c) 3 (d) cannot be determined.
23. Which of the following number contains there significant digits ? (a) 0.200 (b) 0.030 (c) 0.0052 (d) 0.002 24. What is the number of neutrons in Zn2+ ion
(Atomic mass namber = 70) (IITJEE 1979)
(a) 34 (b) 36 (c) 38 (d) 40
25. The same amount of Zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide.
What will be the ratio of volumes of hydrogen evolved ? (IITJEE 1979) (a) 1 : 1 (b) 1 : 2 (c) 2 : 1 (d) 9 :4
26. 2.76g of silver carbonate on being strongly heated yields a residue weighing (IITJEE 1979) (a) 2.16g (b) 2.48 g (c) 2.32 g (d) 2.64 g
27. Find the total number of electrons in one molecule of carbon dioxide.
(a) 22 (b) 44 (c)66 (d) 88
28. A gaseous mixture contains oxygen and nitrogen in the ratio of 1 : 4 by weight. Therefore, the ratio of their number of molecules is
(a) 1 : 4 (b) 1 : 8 (c) 7 : 32 (d) 3 : 16 29. Identify the incorrect unit conversion factor.
(a) 3 1 1 cm mL (b) 1 10 cm mm (c) 60 1min s (d) None of these
6
30. 90 g KClO3 on heating gives 2.96g KCl and 1.92g oxygen. Which of the follwing laws is illustrated by this statement ?
(a) Law of definite proportion (b) Law of mass conservation (c) Law of multiple proporation (d) Avogadro’s law.
31. Match the following property.
A B
(i) Law of Multiple proportions. (p) Richter (ii) Law of Combining volumes (q) Proust (iii) Law of Reciprocal proportions. (r) GayLussac (iv) Law of Constant composition. (s) Dalton
(a) i - s, ii - p, iii - r, iv - q (b) i - s, ii - r, iii - p, iv - q (c) i - s, ii - r, iii - q, iv - p (d) i - q, ii - r, iii - p, iv - s
32. Two oxides of a metal ‘M’ contain 27.6% and 30.0% of oxygen respectively. If the formula of the first oxide is M3O4 , find that of the second.
(a) M O2 3 (b) M O2 (c) MO2 (d) M O3 2
33. Naturally occuring Boron consists of two isotopes having atomic masses 10.01 and 11.01 respectively. Calculate the percentage of both the isotopes in natural Boron (Atomic mass of natural Boron = 10.81) (a) 20% and 80% (b) 80% and 20%
(c) 25% and 75% (d) 75% and 25%
34. Calculate the mass percent of Na and S in sodium sulphate. (a) Na = 16.2%, S = 22.54% (b) Na = 32.39%, S = 11.26% (c) Na = 22.54%, S = 32.39% (d) Na = 32.39%, S = 22.54%
35. Determine the empirical formula of an oxide of iron which has 69.9% iron and 30.1% oxygen by mass. (a) FeO (b) Fe2O3 (c) Fe3O4 (d) Fe3O2
36. Calculate the amount of carbon dioxide that can be produced when 1 mole of carbon is burnt in 16 g of dioxygen.
(a) 44g (b) 22g (c) 88g (d) 11 g
37. Calculate the concentration of nitric acid in moles per litre which has a density , 1.41 g/mL. %w/w of nitric acid is (a) 15.44M (b) 0.064M (c) 0.077M (d) 12.87M 38. In a reaction : N2( )g 3H2( )g 2NH3( )g 2 , 2000g N reacts with 1000g H2 which reactant will left unreacted ? How much ?
(a) N2, 2428g (b) H2, 428.6g
(c) N2, 571.4g (d) H2, 571.4g
39. Calculate the number of sulphate ions in 100mL of 0.001M ammonium sulphate solution.
(a) 19 6.022 10 (b) 19 6.022 10 (c) 20 6.022 10 (d) 20 6.022 10
40. Calculate the molarity of a solution of ethanol in water in which mole fraction of ethanol is 0.040. (a) 2.31M (b) 0.213M (c) 0.0213M (d) 23.1M
7
41. Some statements are given below based on the pictures. Identify true and false statements.
(P) (Q) (R) (i) ‘P’ and ‘Q’ both indicates precision and accuracy.
(ii) ‘Q’ indicates precision and accuracy white ‘R’ indicates neither precision nor accuracy. (iii) ‘P’ indicates precision but not accuracy.
(iv) ‘Q’ indicates both precision and accuracy
(a) FTTT (b) TTTT (c) TTFT (d)FTFT
42. The normality of 0.3M phosphorous acid is (IITJEE 1999) (a) 0.1 (b) 0.9 (c) 0.3 (d) 0.6
43. An aqueous solution of 6.3g oxalic acid dihydrate is made upto 250 mL. The volume of 0.1 N NaOH required to completely neutralize 10 mL of this solution is
(a) 40 mL (b) 20 mL (c) 10 mL (d) 4 mL
44. The pair of the compounds in which both the metals are in the highest possible oxidation state is
(a)
3
3 6 , 6 Fe CN Co CN (b) CrO Cl2 2 ,MnO4 (c) TiO3 ,MnO2 (d)Co CN
63 ,MnO345. In the analysis of 0.0500 g sample of feldspar, a mixture of the chiorides of sodium and potassium is obtained, which weighs 0.1180 g. Subsequent treatment of the mixed chlorides with silver nitrate gives 0.2451g of silver chloride. What is the percentange of a sodium oxide and potassium oxide in feldspar ?
(a) 10.62%Na O2 , 3.58%K O2 (b) 3.58%Na O2 , 10.62%K O2
(c) 10.62%Na O2 , 35.8%K O2 (d) 35.8%Na O2 , 10.62%K O2
46. 5.5 g of a mixture of FeSO4.7H2O and Fe2 (SO4)39H2O requires 5.4 mL of 0.1N KMnO4 solution for complete oxidation. Calculate the number of mole of Fe2 (SO4)39H2O in the mixture.
(a) 0.0095 (b) 0.15 (c) 0.0952 (d) 1.52
47. A compound contains 28% of nitrogen and 72% of a metal by weight. Three atoms of the metal combine with two atoms of nitrogen. Find the equivalent weight of the metal.
(a) 12 (b) 24 (c) 36 (d) 48
48. The density of a 3M Na2|S2O3 solution is 1.25 g per mL, What is the molalities of Na+ and S 2O3
2-ions ?
8
49. Haemoglobin present in blood contain 3.72% by mass iron. Calculate the number of iron atoms in 2.0g of haemiglobin.
(a) 4.53 X 1026 (b) 4.53 X 1023 (c) 5.95 X 1019 (d) 8 X 1020
50. How many moles of magnesium phosphate, Mg3(PO4)2 will contain 0.25 mole of oxygen atoms (AEEE 2006)
(a) 0.02 (b) 3.125 x 10-2 (c) 1.25 x 10-2 (d) 2.5 x 10-2
51. The unit J Pa -1 is equivalent to
(a) m3 (b) cm3 (c) dm3 (d) none of these
52. The density of Al metal is 2.7 gcm-3. An irregularly shaped piece of aluminium weighing 40.0g is added
to a 100mL graduated cylinder containing 50.0mL of water. upto what height the water level will rise in the cylinder ?
(a) 14.8mL (b) 79.6mL (c) 64.8mL (d) 50mL
53. A sample of clay after drying partially was found to contain 50% silica and 7% water.The original sample of clay had 12% water, What is the percentage of silica in the original sample?
(a) 50% (b) 5% (c) 43%(d) 47%
54. In which of the following pairs percent compostion of element is not same ? (a) benzene and ethyne (b) But - 2 - ene and Cyclobutane
(c) glucose and fructose (d) phenol and ethanol
55. What weight of CuO will be required to provide 200Kg copper (a) 200Kg (b) 79.5Kg (c) 250Kg (d) 100Kg
56. Choose the proper option after studying following statement (T = True, F = False) 1. The percent composition of vinyl chloride and its polymer PVC are same.
2. The perecent compostion of phosphorous trioxide (P2O3)is half than that of its dimer phosphorous hexoxide (P4O6) for each of the elements present in them.
(a) T, F (b)F,T (c) T, T (d) F, F
57. Impure sample of ZnS contains 42.34% Zn. What is the percentage of pure ZnS in the smaple ?
(a) 67% (b) 63% (c) 58% (d) 37%
58. If the atomic mass of carbon were set at 50 amu, what would be the value of Avog adro’s number ? (a) 5.01 x 1024 (b) 6.022 x 1023 (c) 1.66 x 1024 (d) none of these
59. For which of the following compounds molecular weigh cannot be determined from atomic weights ? (a) Fe4 Fe CN
6 (b) TiO2(c) TiO1.12 (d) none of these
60. Which one of the following contains greatest number of oxygen atoms ? (a) 1.0g of O atoms (b) 1.0g of O2
9
61. Which of the following chemical equation is incorrectly balanced ? (a) Sb S2 3 12HCl2H SbCl3 6 3H S2
(b) 3IBr4NH3NI33NH Br4
(c) 2KrF2 2H O2 2Kr2O2 4HF
(d) PCl3 3H O2 H PO3 3 3HCl
62. Match the following
Column -I Column -II
(i) Cl2O3 (P) basic anhydride (ii) Li2O (Q) acid anhydride (iii) CO2 (R) base
(a) (i) - (q) (ii) - (p) (iii) - (q) (b) (i) - (r) (ii) - (q) (iii) - (p) (c) (i) - (p) (ii) - (q) (iii) - (r) (a) (i) - (p) (ii) - (q) (iii) - (p)
63. How many g of NaOH can be obtained by reaction of 1 Kg of Na2CO3 with Ca(OH)2 ?
(a) 106 g (b) 850 g (c) 755g (d) 943 g
64. How much calcium oxide (CaO) can be obtained by heating 200 Kg of lime stone theat is 95% pure CaCO3 ?
(a) 56Kg (b) 190Kg (c) 170Kg (d) 107Kg
65. Calculate the amount of NaOH required to neutralize 100 mL 0.1M H2SO4.
(a) 40g (b) 0.4 g (c) 80 g (d) 0.8 g
66. 3g of an oxide of a metal is converted into chloride and it yielded 5 g of chloride. Find the equivalent weight of the metal.
(a) 33.25 (b) 3.325 (c) 12 (d) 20
67. A compound contains two oxygen atoms, four carbon atoms and number of hy drogen atoms is double of carbon atoms. What is the density of vapour of this compound ?
(a) 88 (b) 44 (c) 132 (d) 72
68. The number of molecules in 100 mL of each of O2,NH3 and CO2 at STP are (a) CO2 O2 NH3 (b) NH3 O2 CO2
(c) NH3 = CO2 < O2 (d) NH3 O2 CO2
69. Which of the following represents the formula of a compound which contains 26% nitrogen and 74% oxygen ?
(a) N2O (b) NO (c) NO2 (d) N2O5
70. NKg-1 is the unit of
10 71. Which one of the following statements is incorrect ?
(a) All elements are homogeneous system
(b) Compounds made up of a number of elements are heterogeneous. (c) A mixture is not always heterogeneous
(d) Smoke is a heterogeneous mixture.
72. A balanced chemical equation is in accordance with (a) Avogadro’s law.
(b) Law of constant proportions (c) Law of conservation of mass (d) Law of gaseous volumes.
73. The atomic weights of two elements X and Y are 20 and 40 respectively. If ‘a’ gm of X contains ‘b’ atoms, how many atoms are present in ‘2a’ gm of Y ?
(a) b (b) a (c) 2b (d) (
2
a
)
74. If the components of air are N2 ,78%, O2, 21% ; Ar, 0.9% and CO2, 0.1% by volume, what will be the molecular weight of air ?
(a) 28.9 (b) 32.4 (c) 16.4 (d) 14.5
75. Calculate the molarity of a solution obtained by mixing 50mL of 0.5M H2SO4 and 75 mL of 0.25M H2SO4.
(a) 0.375M (b) 0.35M (c) 0.045M (d) 0.45M 76. Which of the following has the highest normality ?
(a) 1M H2SO4 (b) 1M H3PO3 (c) 1M H3PO4 (d) 1M HNO3
77. In an experiment, 4 gm of M2Ox oxide was reduced to 2.8 gm of the metal. If the atomic mass of the metal is 56 gm/mol, the number of oxygen atoms in the oxide is (AFMC 2010)
(a) 1 (b) 2 (c) 3 (d) 4 78. Match the following
Column - I Column - II
(i) femto (P) 109
(ii) yotta (q) 10-15
(iii) giga (r) 10-18
(iv) atto (s) 1024
(a) i - q, ii - p, iii - r, iv - s (b) i - s, ii - q, iii - p, iv - r (c) i - q, ii - s, iii - p, iv - r (d) i - r, ii - s, iii - p, iv - q
79. The total number of atoms of all elements present in mole of ammonium dichromate is (a) 19 (b) 6.023 x 1023 (c) 114.47 x 1023 (d) 84 x 1023
80. 0.32 gm of a metal on treatment with an acid gave 112 mL of hydrogen at STP. Calculate the equivalent weight of the metal
11
81. For a reaction A + 2B C, the amount of C formed by starting the reaction with 5 moles of A and 8 moles of B is
(a) 5 moles (b) 8 moles (c) 16 moles (d) 4 moles
82. 100 mL of PH3 on heating forms P and H2 . The volume change in the reaction is (a) an increase of 50 mL (b) an increase of 100 mL
(c) an increase of 150 ml (d) a decrease of 50 mL
83. An organic compound made of C, H, and N contains 20% nitrogen. Its molecular weight is (WBJEE 2009)
(a) 70 (b) 140 (c) 100 (d) 65
84. Volume occupied by one molecule of water (d = 1 gm cm -3) is
(a) 9 x 10-23cm3 (b) 6.02 x 10-23cm3 (c) 3 x 10-23cm3 (d) 5.5 x 10-23cm3
85. Calculate the number of moles in 1m3 gas at STP.
(a) 4.46 (b) 44.6 (c) 446 (d) 4460
86. An ore contains 1.24% of the mineral argentite Ag2S by mass. How many grams of this ore would have to be processed in order to obtain 1.0 g of pure solid silver ?
(a) 23.15 g (b) 69.45 g (c) 92.6 g (d) 46.3 g 87. Find the electric charge in couloumb of 9.0 gm of A13+ ions.
(a) 9.6 x 104 (b) 6.9 x 104 (c) 2.9 x 105 (d) 4.80 x 10-19
88. Which of the following is not a homogeneous mixture ?
(a) smoke (b) air (c) Brass (d) Aqueous solution of sugar 89. Which of the following has the largest number of atoms ?
(a) 0.5g atom of Cu (b) 0.635g of Cu (c) 0.25 moles of Cu atom (d) 1 g of Cu
90. 27 g of A1 (at mass = 27) will react with oxygen equal to (IIT 1978) (a) 24 g (b) 8 g (c) 40 g (d) 10 g
91. Two containers P and Q of equal volumes contain 6 g of O2 and SO2 respectively at 300K and 1 atmosphere. Then
(a) No. of molecules in P is less than that in Q (b) No. of molecules in Q is less than that in P (c) No. of molecules in P and Q are same. (d) cannot be determined
92. Which of the following pairs of substances illustrates the law of multiple proportions ? (a) CO and CO2 (b) NaCl and NaBr
(c) H2O and D2O (d) MgO and Mg(OH)2
In each of the follwoing questions, two statements are given, one is Assertion (A) and the other is Reason (R). Examine the statements carefully and mark the correct answer according to the instructions given below :
(a) If both A and R are correct and R is the correct explanation of A. (b) If both A and R are correct and R is not the correct explanation of A. (c) If A is correct R is wrong.
12 93. A : Normality of 0.1M H2SO4 is 0.2N.
R : H2SO4 is a dibasic acid.
94. A : 1 Gram molecule of sulphar also represents 1 gram atom of sulphur. R : Atomicity of sulphur is one.
95. A : In the equation NH3 HCl NH Cl4 , Gay-Lussac’s law is not applicable to NH4Cl.
R : NH4Cl is not a gas,.
96. A : Atomic mass of sodium is 23 u.
R : An atom of sodium is 23 times heavier than an atom of 12C.
97. A : Pure water, irrespective of its source always contain hydrogen and oxygen in the ratio 1 : 8 by mass. R : Total mass of reactants and products remains constant during physical or chemical change.
98. A : Mass numbers of most of the elements are fractional.
R: Mass numbers are obtained by comparing with mass number of 12C.
99. A : The mass of the products formed in a reaction depends upon the limting reactant. R: Limting reactant reacts completely in the reaction.
100. A : Cinnabar is a chemical compound whereas brass is mixture.
R : Cinnabar always contain 6.25 times mercury than sulplur by weight. Brass can have any proportion of Cu and Zn.
101. A : 1 L of O2 and 1 L of O3 contains the same number of moles under identical conditions.
R : Under identical conditions, 1 L of O2 and 1 L of O3 contain the same number of oxygen atoms. 102. A : The standard unit for expressing atomic mass is amu.
R : Now a days amu is represented by ‘u’.
ANSWER KEY 1 c 2 d 3 d 4 a 5 b 6 a 7 c 8 b 9 a 10 d 11 a 12 c 13 a 14 a 15 c 16 d 17 d 18 a 19 d 20 a 21 a 22 b 23 a 24 d 25 a 26 c 27 a 28 c 29 d 30 b 31 b 32 a 33 a 34 d 35 b 36 b 37 a 38 d 39 b 40 a 41 a 42 d 43 a 44 b 45 b 46 a 47 a 48 b 49 c 50 b 51 a 52 c 53 d 54 d 55 c 56 a 57 b 58 d 59 d 60 d 61 c 62 a 63 c 64 d 65 d 66 a 67 b 68 d 69 d 70 d 71 b 72 c 73 a 74 a 75 b 76 c 77 c 78 c 79 c 80 b 81 d 82 a 83 a 84 c 85 b 86 c 87 a 88 a 89 a 90 a 91 b 92 a 93 a 94 d 95 a 96 c 97 b 98 d 99 a 100 a 101 c 102 b
13
SOLUTIONS/HINTS
3. (d)
The redox reaction between potassiumdichromate and Mohr’s salt is :
6 2 2 72 14 6 3 2 3 7 2
Fe Cr O H Fe Cr H O
4. (a)
Number of particles Number of moles No. of moles of carbon 24 2
12
5. (b)
2BC3 3H2 2B6HC
2 mol 3 mol 2 mol = 21.6 g 3 0.0821 273 67.2 1 nRT V L P 6. (a) mass of carbon = 9 108 72 13.5 g
No.of carbon atoms 72 6
12
similarly, no of H and N atoms are 8 and 2 respectively. 8. (b)
During the reaction, Cr O2 72
changes to Cr3+ . Hence the change in oxidation number of Cr is 6.
6 Equivalent weightMolar mass 9. (a)
In 2L solution, there are 0.02 mol Br - ions and 0.02 mole 2 4
so
1 L of mixture X contains 0.01 mol Br– and 0.01 mol 2 4 SO ions. Hence, Y= 0.01 mol Ag Br Z= 0.01 mol BaSO4 10 (d) Mass of an electron 31 9.108 10 Kg 31 1 . s in 1 9.108 10 No of electron Kg 31 23 1 8 1 9.108 10 6.023 10 10 9.108 6.023 mol mol
14 11. (a)
mass of metal = 60 g
mass of oxygen = 40 g mass of oxygen = mass of metal
40 g = 60g 8 g = (?) = 8 60 12 40 25. (a) (i) ZnH SO2 4 ZnSO4 H2
(ii) Zn 2NaOH Na ZnO2 2 H2
26. (c) ( ) ( ) ( ) 2 3s 2 s 2g Ag CO Ag O CO 1 mol 1mol 0.01 mol 0.01 mol
There fore mass of residue (Ag2O) 0.01molarmass of Ag O2
0.01 232 2.32g
28. (c)
The ratio by weight = 1 4 Ratio of moles 1 28 7 32 4 4 32 32 28 32. (a)
Let ‘x’ be the atomic mass of metal ‘M’
In the oixde M3O4, the mass of ‘M’ = 72.4 and that of ‘O’ = 27.6
3 4 72.4 27.6 16 M O x M O 72.4 27.6 : 3 : 4 16 x 56 x
For second oxide, the mass of ‘M’ = 70 and that of ‘O’ =30
70 30 56 16 M O 1.25 1.875 M O 1 1.5 OR 2 3 M O M O
15 33. (a)
Let the % of isotope with atomic mass 10.01 be ‘x’ % of isotope with atomic mass 11.01 = 100-x
Avg at mass = 10.01 (100 )11.01 10.81( ) 100 x x Given 37. (a)
69% w/w means 100 g nitric acid soution contain 69 g of nitric acid by mass.
3
69
1.095 63
moles of HNO
Vol. of 100 g nitric acid solution 100 0.07092 1.41
L
1.095
15.44 0.07092
moles per litre
38. (d) N2 3H2 2NH3 28 g 6 g 2000 g (?) 2000 6 428.6 28 g
But we are given 1000 g H2 There fore 1000 - 4286 = 571.4 g H2 will left.
39. 3(b)
No of moles of (NH4)2SO4 = molarity vol(L) = 0.001 0.1 = 0.0001 2 23 19 4 No of SO. ions 0.0001 6.022 10 6.022 10 40. (a) 2 ( ) ( ) ETOH ETOH ETOH H O n X n n ( ) ( ) 0.04 55.55 ETOH ETOH n n (ETOH) 2.31 n 42 (d)
phosphorous acid(H PO3 3) is a dibasic acid. Its structure is as follows : Normality = basicity x Molarity
= 2 x 0.3 = 0.6 43. (a)
Equivalents of H C O . 2H O in 10ml = Equivalents of NaOH2 2 4 2 6.3 1, 0000 63 250 0.1 40 V mL O P OH OH H
16 44. (b)
The oxidation states of various metals are : (a) Fe 3,Co3
(b) Cr 6,Mn7 (c) Ti 6,Mn4 (d) Co 3,Mn6 45. (b)
Suppose amount of NaCl in the mixture = ‘x’ g The amount of KCl in the mixture = (0.118 - x) g NaCl + AgNO3 AgCl + NaNO3
58.5 143.5 x 143.5 ...( ) 58.5 x g i
Similarly AgCl obtained from KCl = 143.5 (0.118 ) ...( ) 74.5
x
g ii
But (i) + (ii) = 0.2451 g (Given) Amount of NaCl = 0.0338 g Amount of KCl = 0.0842 g Now, 2NaCl = Na2O 117 62 0.03380.0338 0.0338 62 0.0179 117 g 2 0.0179 10 0 % 3.58% 0.5 of Na O ... 46. (a) Weight of 4 2 5.4 0.1 278 7 0.150 1000 FeSO H O g Moles of 2. 4 3 2 5.35 ( ) . 9 0.0095 562 Fe SO H O 47. (a) Atomic Weight Equivalent weight Valency 48. (b) 1000 , 1000 s M m d MM M Molarity of solution d density of solution s
M Molar mass of solute
1000 3 3.865 1000 1.25 3 158
17 51. (a) 3 2 Pr J Work Nm m Pa essure Nm 52. (c) d m v 40 14.8 3 2.7 m V cm d
Water level in cylinder = 50+ 14.8 = 64.8 mL 65. (d)
0.1MH SO2 4 1000mLsolution contains 0.1mol H SO2 4 2 4
100mL solution contains0.01mol H SO
mass of H SO2 4 0.01 98 0.98g 2 4 2 4 2 2 2 2(40) 98 (?) 0.98 80 0.98 0.8 98 NaOH H SO Na SO H O g g g g 66. (a) . . . . . . . . . .
Wt of metal oxide Eq wt of metal Eq wt of oxide
Wt of metal Choride Eq wt of metal Eq wt of Choride
3 8 33.25 5 35.5 E E E 67. (b) M F C H O. . 4 8 2 88 Molar mass 88 44 2 Vapour density 68. (b)
Equal volumes under identical conditions contain equal no. of molecules 69. (d) 26 74 1.85 4.625 2 5 14 16 N O N O N O 70. (d) F ma 1 f N a NKg m Kg
18 73. (a) No of moles of X 20 a . ( ) 20 20 a No of atoms of X N b given b a N 2 . 40 2 . 40 2 20 40 a No of moles of Y a No of atoms of Y N b N b N 74. (a) 78 28 21 32 0.9 40 0.1 44 . . 78 21 0.9 0.1 Mol wt of air 75. (b) No.of moles of 0.05L H2SO4 = 0.5 x 0.05 = 0.025 No.of moles of 0.075L H2SO4 = 0.25 x 0.075 = 0.01875 Total no. of moles = 0.025 + 0.01875 = 0.04375
Total vol = 0.05L + 0.075L = 0.125L 0.04375 0.35 0.125 Molarity M 77. (c) 1 Mol M2Ox = (2 56 + 16x) gm , (2 56 16 ) 112 112 4 4 112 16
Now x gm of oxide gm metal
gm of oxide gm metal x 112 4 2.8 ( ) 112 16 But given x x = 3 79. (c)
Molecular formula of ammonium dichromate is
4 2 2 7 (NH ) Cr O 80. (b) 2 11200 . . wt of metal Eq wt of metal vol of H in ml displaced at STP
19 82. (a) ( ) ( ) 3 ( ) 2 2 2 3 g s g PH P H 2mL 3mL 100ml (?) 100 3 150 2 ml 50 Increase mL 85. (b) 3 1m 1000L , 22.4 1 At STP L mol 1000 1000 44.6 22.4 L 86. (c) 2 248 216 (?) 1.0 1.148 Ag S Ag g g g g 2 100 1.24 (?) 1.148 92.58 92.6 ore Ag S g g g g 87. (a) 3 9 . 0.33 27 No of moles of Al 3 23 23 . 0.33 6.022 10 2 10 No of Al ions 19 23
Electric charge 3 1.602 10 10 9.6 Coulomb
20
The group of molecules is called matter. Matter is made up of small particles. Matter is in three states, Solid, liquid and gas. The other two states are known as Plasma and Bose, Einstein condensate. The physical state of the matter changes by changing temperature. The physical properties of a subtance are changed by changing its physical state but the chemical properties do not change, sometimes the rate of chemical reaction changes by changing the physical state. During the chemical calculation, it is most essential to have the information about the physical state of substances (reactant or product) and hence it is essential to study the physical state of matter, factors affecting and related some important laws. The deciding factors of the physical state of matter are intermolecular forces, molecular interaction and the effect of thermal energy on the motion of particles.
The Dutch scientist van der Waals suggested that the weak forces of attraction exist between the molecules, which cannot be explained by any other chemical attraction is known as van der Waals attractive forces. This force is universal. This force of attraction is exerted upto 4.5A distance in sub-0 stance. van der Waals forces depend upon the shape of molecules, number of electrons present in molecules, contact surface of molecules and average intermoleculer distance. The van der Waals forces of attraction are different like (i) Dispersion forces or London forces. (2) Dipole-dipole forces and (3) Dipole-induced dipole forces.
Dispersion forces of attraction was first of all proposed by the German scientist Fritz London so it is known as London forces. This type of force of attraction is observed in atoms or molecules, there is a temporary dispersion in electron density that affect the electron density of nearby atom or molecule so the force of attraction is developed and so such effect is called dispersion force. The dipole-dipole forces are observed in permantently dipolar molecules. Such dipolar molecules also have interactive London forces so the cummulative effect of both forces are observed. The dipole-dipole force is stronger than London forces. The dipole-induced dipole forces are observed when dipolar molecules come near to non-polar molecules. This type of molecules also have London forces and hence the cumulative effect of both forces are observed. The hydrogen bonding is an important intermolecular force. The first elements of groups 5, 6 and 7 due to their high electronegativity combine with hydrogen to form hydride compounds, in which hydrogen bond is observed. There also exists an intermoleculer repulsive forces; and based on that the effect of pressure on solid, liquid and gaseous state explained very easily. The most important factor which decides the physical, state of matter is the effect of thermal energy, on motion of molecules due to this motion of molecules or atoms the energy produced is called thermal energy to keep the molecules near to each other while the thermal energy has tendency to keep the molecules away from each other. By balancing combination of the two opposite factors, the physical state of matter as solid, liquid or gas is decided. Due to weak forces of attraction between molecules of gaseous state have some characteristics. The behaviour of gas is described by the quantitative relation between mass, volume, temperature and pressure and these relations are discovered by experimental observations and such relations are called laws of gases. The relation between pressure and volume of a gas was studied and it is known as Boyle’s law. At constant temperature for a fixed amount gas, pressure (P) varies inversely with its volume (V). Mathematically the Boyle’s law is written as PV = K or P1V1 = P2V2. The equation d/P = K devised from Boyle’s law where d is the density. The Kelvin temparature is accepted as an SI unit. The relation T = (t + 273.15) K is obtained. On the basis of experimental observations a relation between absolute temperature and volume is obtained, which is known as Charles’
UNIT : 2 STATES OF MATTER
21
law. Mathematically it is written as V = K T or
1 2
1 2
V V
=
T T . The relation between pressure and absoulte temperature (T) is obtained on the basis of experimental orbservations by scientist Gay Lussac and is known as Gay Lussac’s law. Mathematically it is written as P = K
T or
1 2
1 2
P P
=
T T . The relation between volume of a gas and number of molecules was given by Avogadro, which is known as Avogadro’s law. The mathematical form of it is V = K.n. The 00C or 273 K temperature and 1 bar pressure is accepted as a standared value by SI system and hence these values are known as standard temperature and pressure (STP). 1 mole of gas at STP is having volume 22.4 litre and number of molecules equal to 6.022 × 1023 known as molar volume and Avogadro’s number respectively. Combining Boyle’s law and Charles’ law, the relation obtainged PV = K
T or
1 1 2 2
1 2
P V P V
=
T T is known as combined gas equation. The ideal gas equation, PV = nRT is also known as equation of state and R is called universal gas constant which has different values in different units. The real gas behaves as ideal gas at high temperature and low pressure and are called ideal gases. The behaviour of real gas is deviated from ideal gas and its study came from the study of effect of pressure and temperature and so the ideal gas equation is written as
2 2 an P + (V nb) = nRT V æ ö ç ÷
è ø - and this equation is also known as van der Waals equation. The gas can be
liquefied by lowering the temperature and increasing pressure at which gas get liquified is known as critical temperature (TC) and critical pressure (PC) respectively and at critical temperature and critical pressure the volume occupied by 1 mole of gas is called critical volume (VC) and this state is called critical state. The PC, TC and VC values are constant so they are known as critical constants. The liquefication of gas is explained by isotherm. Maxwell and Boltzmann had studied the distriubution of molecules between different possible and plotted graph which is known as Maxwell’s distribution curve.
The total pressure of the mixture of two or more than two gases is obtained by the Dalton’s law. Total pressure (P) = pA + pB + pC + pD .... and the partial pressure (p) is calculated from total pressure by equation p1 = X1 × Ptotal. If the % by volume is given then the partial pressure of gas is caculated using equation.
Partial pressure A
% by volume of gas A × total pressure p =
100 . The Graham’s law of gaseous diffusion is 1
r d
µ and using formula the ratio of rate of diffuson of NH
3 and HCl gas was obtained practically as 1.46 + .01. The application of Graham’s law of gaseous diffusion are as given in the text. The Avogadro’s hypothesis is useful to calculate the number of molecules, atoms and total number of atoms in given amount of gas.
The liquid state has its physical properties like fixed volume, fluidity, non- compressibility, diffusion, evaporation, vapour pressure, surface tension and viseosity.
22
1. What is value of Boyle’s temperature of ethane gas when a= 5.489 dm6 atm mol-2 and b = 0.0638 dm3
atm mol-1
(a) 1048K (b) 104.8K (c) 209.6K (d)290.6K
2. The value of universal gas constant R depends upon the
(a) Temperature of the gas (b) Volume of the gas
(c) Number moles of the gas (d) none of these
3. The Boyle’s temperature for the ideal gases is given by (a) a R (b) a bR (c) 2a bR (d) none of these
4. The ratio of van der Waals’ constants a and b has the dimensions of
(a) atm mole-1 (b) L mole-1 (c) atm . L mole-1 (d) atm mole-2
5. A gas expanse through a porons plug and exhibits cooling if its temperature is
(a) More than inversion temperature (b) Less than inversion temperature (c) Less than critical temperature (d) Less than Boyle’s temperature 6. A gas behaves like an ideal gas at
(a) High pressure and low temperature (b) High pressure and high temperature (c) At low pressure and increasing in volume (d) Decreasing velocity by lowering temperature
7. To which of the following gaseous mixture is Dalton’s law not applicable?
(a) He + Ne + SO2 (b) NH3 + HCl + HBr (c) O2 +N2 +CO2 (d) N2 +H2 +O2
8. The degree of dissociation of cl2 at 1500K is 0.45 according to the reaction Cl2 ® 2Cl assumig that both Cl2 and Chlorine atoms behave like ideal gases, calculate the density of the mixture if the pressure of the mixture is 1.5 atm
(a) 0.596 g. l-1 (b) 0.496 g. l-1 (c) 0.696 g. l-1 (d) 0.396 g. l-1
9. A gas is kept at 1 atm pressure. To compress it to 1/4th of its initial volume, the pressure to be applied is
(a) 1 atm (b) 2.0 atm (c) 4.0 atm (d) 1
4 atm
10.The density of a gas at 300K and 1 atm is d pressure remaining constant, at which of the following temperatures will its density become. 0.75 d ?
(a) 200 C (b) 300 C (c) 400K (d) 300K
11. A mixture contains N2O4 and NO2 in the ratio 2 : 1 by volume. The vapour density of the mixture is
(a) 45.4 (b) 49.8 (C) 32.6 (d) 38.3
23
12. At extremely low pressure, the vander waals equation for one mole of a gas may be written as
(a) PV =RT + pb (b) PV RT a
v
= - (c) PV = RT (d) (p a)(v b) RT v
+ - =
13. The compressibility of a gas is less than unity at STP Therefore
(a) Vm > 22.4 L (b) Vm < 22.4 Litre (c) Vm = 22.4 L (d) Vm = 44.8 Litre 14. The correct order for magnitude of vanderwaals constant b should be
(a) C H2 6 <CO CO< 2 <He (b) CO C H< 2 6 < He CO< 2
(c) C H2 6 <CO2 < CO He< (d) He CO< < CO2 <C H2 6
15. The molecular radius of O2 is 2.88 x 10-10 m calculate the excluded volume per mol of O 2
(a) 0.24 dm3 (b) 0.48 dm3 (c) 0.024 dm3 (d) 0.048 dm3
16. An ideal gas can not be liquefied because
(a) The intermolecular force of attraction between the gaseous molecules are negligible. (b) Its critical temperature is very high
(c) The vanderwaals constants a and b are very high (d) Of all of these
17. The values of ‘a’ for the gases O2 , CO2, N2 and CH4 are respectively 1.36, 3.64, 1.39 and 2.253 L2 atm
mol-1 which gas can be most easily liquefied ?
(a) O2 (b) CO2 (c) N2 (d) CH4
18. The rate of diffusion of H2 is about
(a) 12that of He (b) 1.4 timesthat of He (c) Twice that of He (d) 4 times that of He 19. Most probable speed, average speed, and RMS (root mean square speed) are related as
(a) 1 : 1.224 : 1.128 (b) 1.128 : 1 :1.224 (c) 1 : 1.128 : 1.224 (d) 1.224 : 1.128 : 1.0
20. At room temperature the mixture of SO2 and O2 gas, compared to theO2 molecule, the SO2 molecule will hit the wall with..
(a) Smaller avarage speed (b) Greater average speed
(c) Greater kinetic energy (d) Greater mass
21. Which has maximum value of mean free path ?
24
22. 4.0 gm ideal gas is filled in a bulb having volme 10 dm3 at a constant temperature T & constant
pressure P. If 0.8 gm gas is removed from the bulb to maintain the original pressure at (T + 125)K temperature, what would be the value of T for a gas having molar mass 40 gm mole-1.
(a) 500K (b) 5000C (c) 773K (d) 7730C
23. What would be vlaue of ratio for RMS and average speed of gaseous molecules at a constant temperature ?
(a) 1.086 : 1 (b) 1 : 1.086 (c) 2 : 1.086 (d) 1.086 : 2
Hint - 2 2
Pressure and Temperature are constant
1 1 2 2 1 2 1 2 1 2 1 2 1 1 : 3.2( 125) 4 3.2 400 0.8 400 500 So n T n T W W T T M M M M W T T T T T T K = ´ = = = + = + \ = \ =
24. If temperature T2 > T1, which graph of maxwell Botlzmamn distriburibution of molecular speed is correct ? (a) N° O T1 T2 Molecular Speed (b) N° O T1 T2 Molecular Speed (c) N° O T1 T2 Molecular Speed (d) N° O T1 T2 Molecular Speed
25. The RMS velocity of an ideal gas at constant pressure varies with density relates as
(a) d (b) d (c) d2 (d) 1
25
26. The ratio of rms (root mean square ) velocities for two different gases is
(a) 1 2 1 2 V M M V = (b) 1 2 2 1 m m M = M (c) 1 2 2 1 M M µ = µ (d) 2 1 1 2 M M m = m
27. At constant temperature, a gas is filled at 1 atm pressure in a closed container. To compress this gas to 1
4 th of its intial volume, the pressure to be applied is (a) 4 3atm (b) 2 atm (c) 1 4 4 th atm (d)1 3atm 28. What is the pressure of 380 mm Hg column of a gas in pascal ?
(a) 5.05 x 104 Pa (b) 5.06 x 105 Pa (c) 0.505 x 103 Pa (d) 1.013 x 105 Pa
29. The graphs plotted V® T for one mole of an ideal gas as follows , which graph represent its ideal behaviour at atmospheric pressure ?
(a) V (L) (22.4L, 273K) (38.8L, 37 3K) T (K) (b) V (L) (22.4L, 273K) (38 .8L, 37 3K) T (K) (c) V (L) (22.4L, 273K) (30. 6L,373 K) T (K) (d) V (L) (22.4L, 273K) (14.2L , 373K) T (K)
30. Helium gas is compressed to half of the volume at 303 K. It should be heated to which temperature for its volume to increase to double of its original volume ?
(a) 303K (b) 606K (c) 1212K (d) 300C
31. When a gas is heated from 298K to 323K at a constant pressure of 1 atm its volume is (a) Increases from V to 1.8 V (b) Increases from V to 1.08 V (c) Increases from V to 1.5 V (d) Increases from V to 2 V
26 Hint 1 5 4 380 380 380 760 0.987 10 380 (?) 380 5.05 10 760 mm torr atm atm Pa atm mm Pa = = \ = \ = \ = ´ Hint 2
At const pressure according to charles law
1 2 1 2 22.4 0.082 ...( ) 273 30.6 0.082...( ) 373 V V K T T I and II = = \ = = (I) and (II) constant behaves the gas as an ideal
Hint - 3 : According to Charles’ law
1 2 1 303 1 2 1 1 2 V V V K V at T K T =T = = = 2 1 2 ? 2 2 1 2 1 V T T V V at T V \ = = = 21 303 1 2 V v ´ = =303 4 1212K´ =
Hint 4 : According to Charles’ law
1 2 1 2 1 2 298 323 323 1.08 2 298 1 1 V V T T V V V V V = = \ = =
32. At 200 and 760 torr, the sample of air contains 20% O
2 & 80% N2 gaseous mixture, find the density of
the air (Molarmass O2 = 32 g/mol , N2 = 28 g/mole R =0.082 liter mole-1 K-1)
(a) 1.918 gL-1 (b) 2.198 gL-1 (c) 1.198 gL-1 (d) 1.394 gL-1
33. The ratio of velocities of diffusion of gas A and B is 1 : 4, if the ratio of their masses in a mixtare is 2:3, calculate the ratio of their mole fractions (BIT 1990)
(a) 1 : 12 (b) 1 : 24 (c) 1 : 6 (d) 4 : 3
V (L)
(22.4L, 273K) (30.6L, 373K)
27
34. Under same conditions of temperature and pressure the volumes of 14g N2 and 36g of O3 are related as :
(a) 2VN2 = 3Vo3 (b) 3VN2 =2Vo3 (c) 3VN2 =4Vo3 (d) 4VN2 =3Vo3
35. Equal masses of Hydrogen and oxygen gases are placed in a closed container, at a pressure of 3.4 atm. The contribution of hydrogen gas to the total pressure is
(a) 1.7 atm (b) 0.2 atm (c) 3.2 atm (d) 3.02 atm
36. The kinetic energy of 4.0 moles of N2 gas at 1270C is (R =2 cal mole-1K-1)
(a) 4400 cal (b) 3200 cal (c) 4800 cal (d) 1524 cal
37. The critical temperature of H2O is higher than CO2 because (IIT 1997)
(a) fewer electrons than CO2 (b) It contains 2- covalent bonds (c) Molecular shape is V- shape (d) dipole moment of H2O 38. The compressibility factor of an ideal gas is
(a) zero (b) 1 (c) 2 (d)4
39. A 10 L cylinder of nitrogen at 4.0 atm pressure and 270C– developed a leak. When the leak was
repaired 2.36 atm of nitrogen remained in the cylinder at 270C. How many grams of nitrogen escaped?
(a) 18.7g (b) 0.67g (c) 52.6g
(d) 10.0g
40. Calculate percentage of NO2 by weight in N2O4 which has vapour density of 36.
(a) 27.7% (b) 67.7% (c) 52.6% (d) 25.7%
41. Two gases A and B having the same temperature T, same pressure P and same volume V are mixed. If the mixture is at the same temperature T and occupied a volume V, the pressure of the mixture is ..
(a) 2P (b) P (c) P/2 (d) 4P
42. The density of nitrogen is maximum at
(a) STP (b) 273K and 2 atm (c) 546K and 1 atm (d) 546 K and 2 atm
43. The temperature at which real gases obey the ideal gas laws over a wide range of pressure is called
(a) Critical temperature (b) Inversion of temperature
(c) Boyle’s temperature (d) Reduced Temperature
44. Which of the fallowing gases with have the highest rate of diffusion
(a) O2 (b) CO2 (c) NH3 (d) N2
45. At a given temperature Qx= 39y and My= 2Mx whaere Q and M stand for density and molarmass respectively the ratio of Presures px/py would be
28
46. The density of methane at 2.0 atmosphere prassure at 270c is
(a) 0.13 gl-1 (b) 0.26 gl-1 (c) 1.30 gl-1 (d) 26.0 gl-1
47. The diffusion of methane at a given temperature is twice that of gas x. The molecular weight and the gas is
(a) 64.0 SO2 (b) 32.0 (O2) (c) 4.0 (He) (d) 30.0(C2H6)
48. The compressibility factor of an ideal gas is (AIIMS - 1997, IIT91997)
(a) 0 (b) 0.1 (c) 0.2 (d) 0.4
49. As temperature is raise from 200C to 400C, the average kinetic energy of neon atoms changes by a
factor of which of the follwoing ? (a) 1 2 (b) 2 (c) 313 293 (d) 313 293 50. If V rms is 30 R 1/2 at 270C calculate the molar mass of the gas in kilogram (DPMT 2005)
(a) 1 (b) 2 (c) 4 (d)0.001
51. Gas eqution PV=nRT is obeyed by (BHV 200)
(a) only isothermal process (b) only adiabatic process (c) both a and c (d) none of these 52. The average kinetic energy of an ideal gas per molecule in SI unit at 250C will be (CBSE 1996)
(a) 6.17 x 10-21 KJ (b) 6.17 x 10-21 J (c) 6.17 x 10-20J (d) 7.17 x 10-20 J
53. The vapour density of pure ozone would be
(a) 48 (b) 32 (c) 24 (d) 16
54. Equal masses of CH4 and H2 are mixed in an empty container at 250C. The fraction of the total pressure
exerted by H2 is (a) 1
2 (b) 89 (c) 19 (d)
16 17 55. The ratio between the root mean square (rms) vlocity of H2 at 50L that of at 800 K is ?
(a) 2 (b) 4 (c) 1 (d)1
4 56. A real gas behave more ideally at (IIT flrelining 1993)
(a) Low temperature and low presure (b) Low temperature and high presure (c) high temperature and low presure (d) high temperature and high presure
29 57. According to the kinetic theory of gases (IIT 1991)
(a) The pressure exerted by a gas is proportional to mean square velocity of the molecules.
(b) The pressure exerted by the gas is proportional to the root mean square velocity of the molenles. (c) The root mean square velocity is invesly proportional to the temperature
(d) The mean transtational K.E of molecule is direlty propostional to the alsolute temperature
58. The value of vander waals constant a for gses O2, N2, NH3 and CH4 are 1.36, 1.39, 4.37 and 2.253 L2 atm mol-1 respectively the gas which can liquefied most easily will be
(a) O2 (b) N2 (c) NH3 (d) CH4
59. A certain sample of a gas volume 0.24Liter measared at 1.0 atm pressure and 2730C its volume will be
(BHU 2005)
(a) 0.4L (b) 0.8L (c) 27.8L (d) 55.6L
60. If a volume containg gas is compressed to half, how many moles of gas remained in the vessel
(a) Just double (b) just half (c) same (d) more than double
61. At constant Volume for a fixed number of a moles of a gas, the pressure of the gas increases with the rise in tempreture due to (IIt 1992)
(a) Increase in average molecules speed (b) Increase rate of collisions amongst (c) Increase in molecular attraction (d) Increase in mean free path
62. Equal mass of methane and oxygen are mixed in an empty container at 2500C the fraction of the total
pressure exarted by O2 is (a) 1 2 (b) 2 3 (c) 273 1 3 298´ (d) 13
63. Find the true and false statements from the following on the basis of given graph
0.1 0.2 0.3 0.4 0.5 2 4 6 8 10 12 Maximum probable speed
Molecular Speed cm/s F ra ct io n of M ol ec ul es co ll id in g
30
1. Maxwell and Boltz mann had studied the distribution of molecules between different possible speeds
2. This graph is known as maxwell’s distribution curve in which kinetic energy and molecular speed of gas is studdied.
3. The fraction molecues with very high or very low speed is very high
4. Inecresing the speed fraction also increasing Which becomes maximum and then deereases. 5. The top portion of curve indicates maximum fraction of molewles and the speed of molecules is
called most probable speed which is indicated byµ
6. On increasing temperature the collison of molecules increases and speed of molecules decreases
(a) TTFTTF (b) TFTTFT (c) FTTFFT (d) TTTTFF
64. When a real gas behaves as an ideal gas ?
(a) Inter molecular attraction among molecules are negligible then (b) At very low pressure and high temperature then
(c) When molecular size is very very small and negligible to the volume of container then (d) In all the above condition
65. What is the ratio of diffusion rate of 238 6
UF and 235 6
UF When these gases are diffused under the same condition of temperature and pressure ?
(a) 0.09953 (b) 1.0047 (c) 1.0 (d) 10487
66. Molecular mass of SO2 gas is 4 times than CH4 therefore (a) Being so2 and CH4 both gases, they diffuse with same rate (b) so2 gas will diffuse 4 times factor than that of CH4
(c) Diffusion of SO2 gas is half than that of CH4 (d) CH4 gas found 4 times faster than SO2
67. 50 ml O2 gas diffused in 80 sec, What time will be required to diffuse same volume of He gas?
(a) 22.89 sec (b) 28.29sec (c) 92.82 sec (d) 24.29 sec
68. What is the mass (weight) of 6.022 x 1022 oxygen molcules ?
(a) 32 gms (b) 3.2 gms (c) 16 gms (d) 1.6 gms
69. How many molecules of 502 gas will be present in 5.6 litre volume of STP ?
(a) 1.5 10´ 23 (b) 6.002 10´ 23 (c) 7.52 10´ 23 (d) 3.01 10´ 23
70. Molar mass of CaCO3 = 100 gm/mole, how many moleunles are present in 20 gm (aCO3) ? (a) 12.44 10´ 23 (b) 1.2044 10´ 23 (c) 1.2044 10´ 25 (d) 1.2044 10´ 22
31 will be available in its 10 litre volume ?
(a) 10 P RT ´ (b) 1 10 P RT ´ (c) 10 RT P ´ (d) 1 10 RT P ´ STP P1 = 1.5 bar P2 = 1 V1 = 200 ml V2 = ? T1 = 400K V2 = 273 1 1 2 2 1 2 PV PV T = T 1 1 2 2 1 2 PV T V T ´ P 1.5 200 273 400 1 ´ ´ ´
72. At constant temperature 270C and pressure, 5 litre gas is raised its temperature by 10C, What will be the
change in its volume ? (a) 1
234
th
part of its original volume will be increased.
(b) The volume at 300K acquired by a gas will be increased of its 1 234
th
part (c) The volume of a gas acquired at O L kmp; will be increased of its 1
234
th
(d) 1 234
th
part of volume of a gas at O0C , will be increased.
73. At 400 K temperature , pressure of 200 ml N2 gas is 1.5 bar, What is its volume at STP?
(a) 204.7 ml (b) 20.47 ml (c) 402.7 ml (d) 40.27 ml
74. What is correct prediction from the given graph ?
C 1.0 PV Z RT = H2 He CH4 CO2
32
(a) H2 gas is less compressible than an ideal gas as its z > 1.0 (b) CO2 gas is more compressive than the ideal gas as Z > 1.0 (c) CH4 gas is higher compressive its Z < 1 than the ideal gas (d) a and c both
75. It A,B,C, and D are the graphs plotted for H2, He, CH4 and CO2Q-75 gases which graph is related for fH 2
and CH4 compared to an ideal gases
1.0 PV Z RT = D B A C
(a) D and A (b) A and B (c) A and D (d) B and C
76. which state of matter whose the intermolecular attractive force do not exist ?
(a) solid (b) liquid (c) gas (d) none
77. Which word of the following does not used for states of matter ?
(a) Bose - Einstin (b) Boyle - Einstein (c) plasma (d) solid, gas, liquid 78. 14.2 kg LPG is diffused in a gas cyllinder at 2.5 atm. If 50% lf LPG gas is used up then what will be the
pressure of gas will remain in cyllinder ?
(a) 2.5 atm (b) 1.25 atm (c) 5.0 atm (d) 14.2 2.57.1 V´´
79. When the unit of R = 8.314 x 107 erg. mole-1k-1 . What are the units of pressure and volume of a gas ?
(a) P - dyne cm-2, V-cm3 (b) P - paxal, V-cm3
(c) P - newton m-2, V-cm3 (d) P - atm, V-cm3
80. unit of R in CGS system is
(a) 7 1 1
8.314 10 erg K mole´ - - (b) 1 1
8.314 JK mole- -(c) 0.082litre atm mole K-1 -1 (d) 1.987 cal mole K-1 -1
81. What is the value of gas constant R cal.mol-1K-1 ?
33 82. What is not rateted to Z ?
(a) z=1 states the ideal behaviour of the gas (b) Gases which has z =1 are an ideal gases (c) z is the ratio of PV
nRT known as compressibility factor
(d) When z < 1 of z > 1, the gases convert into their liqud state 83. Which equation is the ideal gas equation for the real gases ?
(a) PV = nRT (b) PV = iRT (c) 2 2 (P am )(V nb) CRT v = - = (d) 2 2 (P am )(V nb) nRT v = - =
84. Proportion of O2,U2 and N2 gases are 3 :2: 5, and the Total pressure of this gas mixture container is 50 bar, What are the partial pressure of cl2 and N2 gases respectively?
(a) 10 bar, 25 bar (b) 10 bar, 15 bar (c) 15 bar, 25 bar (d) 25 bar, 15 bar 85. Which factor is the deciding factor of physical state of matter ?
(a) inter molecular forces (b) molecular interaction
(c) effect of thermal energy on the motion of partcles (d) Given all.
86. Whichphysical state is accuired by water in between temperature above than 273 K and below 373 K?
(a) plasma (b) liquid (c) solid (d) Gas
87. Which physical state of water is more compressable applying pressure at constant temperature ?
(a) Ice (b) water (c) Vapour (d) Plasma
88 Which sabstance can be easily poored form one container into the other at room temperature ?
(a) Kerosene (b) Ice (c) salt (d) all
89. Match column I with column II
column I column II
i) Gas (a) Easily povred form one container to the other
ii) Liquid (b) difinite shape and fixed volume like a container is acquired iii) Solid (c) stats to melt at a definite temperature
(d) At constant pressure the increasing in temperature raises Volume effectively (A) i) - b, ii) - a, iii) - c (B) i) - a, ii) - b, iii) - c
