# Significant Figures, Unit Conversions, and Matter

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Significant Figures, Unit Conversions, and Matter 1) Convert the following to scientific notation:

a) 73 d) 0.0000843

b) 0.023 e) 0.00568

c) 6590 f) 416500

2) Convert the following from scientific notation:

a) 6.3 x 10-7 c) 7.558 x 10-3 b) 5 x 106 d) 2.001 x 109 3) Carry out the following conversions a) 8.79 x 10-4 L to mL d) 1.56 μg to g b) 5.68 m to cm e) 2.5 L to mL

c) 117 mg to g f) 6.72 x 10-7 kg to mg

4) Perform the following operations. Show the correct number of significant figures

A) 50.35 x 0.106 – 25.37 x 0.176 B) 1252.7 – 9.4 x 102 x 12.3 C) ( 0.562 x 19.34 – 7.00) x 4.321

D) (0.4821 + 0.3285) / (0.0123 – 0.113) E) 25.00 x 0.1000 – 15.87 x 0.1036

5) How many sig figs are in the following numbers?

a) 236 m d) 6532.000000 g b) 2000 people e) 8500 L

c) (1000 m)/(1 km) f) 5.226 x 10-12 g

6) Classify each of the following as either a chemical change (primarily) or a physical change.

a) electrolysis of water b) separating an alcohol-water mixture c) formation of fog d) burning wood

e) rusting iron f) converting sand to glass

7) Draw a graph of temperature vs. energy showing the phase changes. Be sure to label all the

phases, phase changes, melting points, boiling points etc.

8) For each of the following write whether it is a mechanical mixture (M), a solution (S), or a compound (C).

a) soda pop b) sugar c) milk d) muddy water e) baking soda (NaHCO3) f) pizza g) bronze

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Bonding and Nomenclature

1) Write the chemical formula for the following compounds AND identify as acid, ionic, or covalent:

A. chlorine tetroxide B. trisilicon tetranitride C. iron(III) hydroxide D. radium carbonate E. hydrobromic acid F. disilicon hexaiodide G. sulfurous acid H. chromium(II) oxalate I. phosphoric acid

2) Write the name of the following compounds AND identify as acid, ionic, or covalent:

A. CoF3 B. PBr5 C. KMnO4 D. FeC2O4

E. HNO3 F. Sn(CN)2 G. LiOH H. Na2HPO4

I. Cu(NO3)2 J. NH4NO3 K. N2S5 L. CuSO4

3) What is the difference between alkanes, alkenes, alkynes, and alcohols?

4) Draw:

a. 1,3,3-trifluoro-2-pentanol b. 3,4,5,6-tetraethyl-nonane c. 2-octyne

d. 3,5-diethyl-4-methyl-heptane e. cyclooctene

f. 2-bromo-3-heptyne g. 3-chloro-1-cyclobutanol h. 1-ethyl-3-propyl-benzene i. 1,3-cyclohexadiene

j. 2,2,3,3-tetrabromo-pentane 5) Name the following:

a. b.

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c. d.

The Mole

1. What is the molar mass of the following compounds?

a. Pb(C2O4)2

b. Ni(OH)2

c. Tin (IV) acetate pentahydrate d. CH3COOH

2. Calculate the mass of the following:

a. 7.01 mol of SiF4

b. 6.59 x 10-4 mol H3PO4

c. 0.0765 mol Li2HSO4

d. 6.85 mol CH3CH2CH2CH2CH3

3. Calculate the number of moles of the following a. 8.00 kg CrS

b. 76.3 mg of I2

c. 2.00 L of N2 at STP d. 35 g of Au

4. Calculate the number of atoms in the following:

a. 1 molecule of CH3COOH b. 70 molecules of BrF5

c. 2.78 mol NiSO4

d. 8.5 L of HCl gas at STP

5. What is the percentage composition of each element in a. (NH4)2SO4

b. Cr3(PO4)2

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6. What is the empirical formula for the following compounds?

a. 26.6% K, 35.4% Cr, 38.0% O b. 46.2% C, 7.69% H, 46.2% O c. 72.4% Fe, 27.6% O

7. What is the volume of 37.84mol of CO2(g) at STP?

Stoichiometry and Reactions

1) Translate the word equations into chemical symbols and balance the resulting equations.

Include phases where stated. Include energy in the equations where appropriate.

a) lithium + water → lithium hydroxide + hydrogen (exothermic)

b) hydrogen chloride gas, when heated, decomposes to hydrogen gas and chlorine gas

c) water is separated by electrolysis into hydrogen gas and oxygen gas

d) solid iron (II) oxide and carbon powder react to form molten iron and carbon dioxide gas

e) Gaseous chlorine gas reacts violently with solid sodium to form solid sodium chloride

2) Balance the following equations and classify each reaction as one of:

synthesis,

decomposition, single replacement, double replacement, neutralization or combustion.

a) __Sr + __O2 → __SrO

b) __C6H12O6 + __O2 → __CO2 + __H2O c) __H3PO4 + __KOH → __K3PO4 + __H2O d) __H2O→__H2 + __O2

e) __Fe(HCO3)3 + __MgSe → __Fe2Se3 + __Mg(HCO3)2

f) __Br2 + __KCl → __KBr +__ Cl2

9) a) What mass of CuO is required to make 18.0 g of Cu according to the reaction

2 NH3 + 3 CuO → N2 + 3 Cu +3 H2O

b) If the reaction actually produces 6.5 g of Cu, what is the % yield?

Periodic Table, Atomic Theory

1. Which atom is bigger: Bi or P? Why?

2. Complete the following table:

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Atom/Ion Atomic # Mass # Protons Neutrons Electrons

39K+1

41Ca

69Ga+3

37C -1

18O

235U+4

3. Naturally occurring silver consists of 51.8% Ag-107 and 48.2% Ag-109.

What is the expected average molar mass of a sample of natural silver, expressed to 3 decimal places?

4. What are the electron configurations for:

a) P b) Cl c) Ar d) F-1 e) S-2 f) He

5. Name at least one trend among each of the following periodic families:

a. Alkali Metals

b. Alkaline Earth Metals c. Halogens

d. Noble Gases

6. If a noble gas could form a +1 ion, which if the noble gases would form a +1 ion most easily?

7. With respect to electrons, how does an ionic bond differ from a covalent bond?

8. Indicate whether the following compounds are ionic, nonpolar covalent, or polar covalent. Explain.

a) NaCl b) H2O c) NO2 d) CS2

9. How many valence electrons are there in:

a) Si b) K+1 c) Ne d) O-2 e) H-1 f) N

10. Draw electron dot structures (Lewis Structures) for:

a) C2H4 b) H2 c) PO4-3 d) HCN e) NH4+1

11. Give examples of molecules with the following shapes:

a) linear b) trigonal planar c) bent d) trigonal pyramidal e) tetrahedral

Solutions, Acids, and Bases

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1. What will be the molarity of the solution created when 60.0 g of BaCl2(s) is dissolved in 600.0mL of H2O?

2. Complete the table below.

pH pOH [H+] [OH-]

2.59

3.12

4.56 x 10 -4

6.98 x 10 -5 4.33

3. What is the molality 250 g of MgCl2 dissolved in 2.5 kg of H2O?

4. What is the mole fraction of NaCl in a mixture that has 45 g of NaCl and 35 g MgCl2?

5. Compute the mass needed to make 500.0 mL of solution at the indicated molarity.

a. 0.85 M H2SO4

b. 4.1 M Mg(OH)2

c. 0.069 M NaBr

6. What is the concentration of BaCl2 if you mix 25.0 g of BaCl2 into 450.0 mL water?

7. What would the final concentration be if you added 30.0 mL of water to 15.0 mL of 1.750 M NaOH?

8. How many grams of Li3PO4 are contained in 7.45 L of 0.175 M Li3PO4(aq)?

9. What would the final concentration of RbCl be if you mixed 250.0 ml of 0.250 M RbCl with 350 mL water?

Kinetics

1. Calculate the equilibrium, K, for the processes given below:

a. 3 H2 (g) + N2 (g) ↔ 2 NH3 (g) [H2] = 0.85 M, [N2] = 1.33 M, [NH3] = 0.22 M

b. 2 NO (g) + Cl2 (g) ↔2NOCl (g) [NO] = 0.67 M, [Cl2] = 0.0029 M, [NOCl] = 0.042 M

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2. Calculate the total pressure of a system that has a mixture of gases that have pressures of 4.5 atm, 3.5 atm, 1.2 atm, and 6.5 atm respectively.

3. Write the reaction that has the following equilibrium expression: K = [A]2[B]2 / [D][C]3

4. What is the direction of shift if you do the following to the reaction in question 3 prior to it reaching equilibrium?:

a. Remove products b. Increase reactants c. Increase pressure d. Increase temperature

5. Calculate the pressure of a container if the volume is increased from 24 mL to 50 mL if the initial pressure was 3.4 atm.

6. What is the temperature of a system that has an initial volume of 35 mL and a final volume of 15 mL if the final temperature was 14 oC?

7. What is the number of moles of gas present if there is a pressure of 2.4 atm, a volume of 4.5 L and a temperature of 15 oC?

8. A weather balloon is filled with 0.295 L of helium on the ground at 18 oC and 756 torr. What will the volume of the balloon be at an altitude of 10 km where the temperature is – 48 oC and the pressure is 0.14 atm?

9. Assume that the mole fraction of nitrogen in the air is 0.8902. Calculate the partial pressure of N2 in the air when the atmospheric pressure is 820 torr.

Thermodynamics

1. The specific heat of aluminum is 0.89 J/goC. How much energy is required to raise the temperature of a 15.0 gram aluminum can 18 oC?

2. What is the value of G if H is – 45 kJ, T is 15 oC, and S is 259 J/oC?

3. Does entropy increase or

decrease?

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4. Does entropy increase or decrease?

5. How many joules are required to heat 250 grams of liquid water from 00 to 1000 C ?

6. How many joules are required to boil 150 grams of water? The heat of vaporization of water is 40.67 kJ / mole.

7. How many joules are required to melt 100 grams of water? The heat of fusion of water is 6.01 kJ / mole.

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