Homework Chapter 1:
Q1 – Q10: 1 point each,
Q11 – Q20: – 2 points each (show calculations / steps to the answer)
Q21 – Q26: – 5 points each (show calculations / steps to the answer)
1. Which one of the following is an example of a physical property? (Section: 1.6)
A) dynamite explodes
D) ice floats on top of liquid water
B) meat rots if it is not refrigerated
E) a silver platter tarnishes
C) gasoline burns
Ans: D
2. All of the following are properties of tin. Which one is a chemical property of tin?
(Section: 1.6)
A) Tin can be hammered into a thin sheet.
B) At –40C a sheet of tin crumbles to a gray powder.
C) Tin melts at 231.9°C.
D) When a bar of tin is bent, it emits an audible “cry”.
E) Tin erodes when added to hydrochloric acid, and a clear gas forms.
Ans: E
3. The SI prefixes nano and deci represent, respectively: (Section: 1.7)
A) 10–9 and 10–6.
D) 109 and 10–6.
6
–3
B) 10 and 10 .
E) 10–9 and 10–1.
C) 103 and 10–3.
Ans: E
4. The SI prefixes milli and mega represent, respectively: (Section: 1.7)
A) 106 and 10–6.
D) 10–3 and 109.
B) 10–3 and 106.
E) 10–6 and 10–3.
3
–6
C) 10 and 10 .
Ans: B
5. The SI prefixes kilo and centi represent, respectively: (Section: 1.7)
A) 103 and 10–2.
D) 10–6 and 102.
6
–1
B) 10 and 10 .
E) 102 and 10–3.
C) 10–3 and 10–2.
Ans: A
6. Mass, length, and volume are extensive properties, but density is an intensive property.
(Section: 1.6)
True / False
Ans: True
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Chapter 1: Chemistry: The Study of Change
7. 20C is colder than 40F. (Section: 1.7)
True / False
Ans: False
8. 6.0 km is how many micrometers? (Section: 1.7)
A) 6.0  106 µm
D) 1.7  10–4 µm
–7
B) 1.7  10 µm
E) 6.0  103 µm
C) 6.0  109 µm
Ans: C
9. 2.4 km is how many millimeters? (Section: 1.7)
A) 2,400 mm
D)
4
B) 2.4  10 mm
E)
5
C) 2.4  10 mm
Ans: D
2.4  106 mm
2.4  10–5 mm
10. In 1828, the diameter of the U.S. dime was changed to approximately 18 mm. What is
this diameter when expressed in nanometers? (Section: 1.7)
A) 1.8  109 nm
D) 1.8  10–5 nm
B) 1.8  107 nm
E) 1.8  10–10 nm
1
C) 1.8  10 nm
Ans: B
11. Liquid nitrogen boils at –195.8C. Express the boiling point of liquid nitrogen in kelvin.
(Section: 1.7)
A) –469.0 K
B) –77.4 K
C) all temperatures are 0 K on the Kelvin scale
D) 77.4 K
E) 469.0 K
Ans: D
12. Express the number 0.000053 in scientific notation. (Section: 1.8)
5.3  10-5
13. Convert 500. milliliters to quarts. (1L = 1.06 qt) (Section: 1.9)
A) 1.88 qt B) 0.472 qt C) 0.528 qt D) 4.72  105 qt E) 5.28  105 qt
Ans: C
14. What are the three states of matter? (Section: 1.5)
Ans: Solid, liquid, and gas
15. Classify the following as an element, a compound, or a mixture: Table salt (non-iodized).
Ans: Compound
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Chapter 1: Chemistry: The Study of Change
16. Suppose a house has a floor area of 2,250 square feet. What is this area in units of square
centimeters? (Section: 1.9)
A) 2.42 cm2
D) 6.86  104 cm2
B) 2.09  106 cm2
E) 101 cm2
C) 5.02  104 cm2
Ans: B
17. Bromine is a red liquid at 25C. Its density is 3.12 g/cm3. What is the volume of 28.1 g
of liquid bromine? (Section: 1.9)
A) 87.7 cm3
D) 28.1 cm3
3
B) 0.111 cm
E) None of the above.
C) 9.01 cm3
Ans: C
18. An object sinks when placed in water if the mass of the object is greater than the mass of
the water that the object displaces. Which of the following objects will sink when
dropped into a bucket of water? (Section: 1.7)
(Given: density of water = 1.00 g/cm3)
A) a cube of aluminum (density = 2.702 g/cm3)
B) a diamond (density = 3.51 g/cm3)
C) a chunk of dry ice (density = 1.56 g/cm3)
D) a chunk of sodium (density = 0.91 g/cm3)
E) a sphere of magnesium (density = 1.74 g/cm3)
Ans: everything except D
19. You just measured a block of wood and obtained the following information:
(Section: 1.9)
mass = 55.120 g
length = 8.5 cm
height = 4.3 cm
width = 3.3 cm
Determine the volume and density of the wood block.
Ans: Volume of the wood block = 120.6 cm3; density of the wood block = 0.46 g/cm3.
Page 3
Chapter 1: Chemistry: The Study of Change
20. You just measured a metal cylinder and obtained the following information:
(Section: 1.9)
mass = 3.543 g
diameter = 0.53 cm
height = 4.4 cm
Determine the volume (V) and density of the cylinder. (V=r2 h, where r = radius, h =
height,  = 3.14)
Ans: Volume of the cylinder = 0.97 cm3; density of the cylinder = 3.65 g/cm3.
21. Radio waves travel at the speed of light, which is 3.00  108 m/s. How many minutes
does it take for a radio message to reach Earth from Saturn if Saturn is 7.9  108 km from
Earth? (Section: 1.9)
Ans: D (43.8 or 43.9 min)
22. The density of lead is 11.4 g/cm3. Express this density in pounds per cubic foot.
(Section: 1.9)
Ans: 711.68 (678.57) lbs/ft3
23. Which of the following speeds is the greatest? (1 mile = 1609 m) (Section: 1.9)
A) 40 mi/h
D) 0.74 km/min
5
B) 2.0  10 mm/min
E) 400 m/min
C) 40 km/h
Ans: A
24. Calculate the mass of the air contained in a room that measures 2.50 m  5.50 m  3.00 m
(density of air = 1.29 g/dm3 at 25C). (Section: 1.9)
Ans: 53.2 kg (53,212 g)
25. Lead melts at 601.0C. What temperature is this in F? (Section: 1.7)
Ans: 1,114 (1113.8) F
26. The highest temperature ever recorded in Phoenix, Arizona, was 122F. Express this
temperature in C. (Section: 1.7)
Ans: 50.0C
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Homework Chapter 2:
All questions 2 points each, (show calculations / steps where
required)
Page 4
Chapter 1: Chemistry: The Study of Change
1.0 What do we call atoms of the same elements with different mass numbers?
Ans: Isotopes
2.0 What is the mass number of an iron atom that has 28 neutrons?
Ans: 54.845 (54)
3.0 For each of the following species, determine the number of protons and the number
of neutrons in the nucleus:
3 He, 4 He, 24 Mg, 25 Mg, 48 Ti, 79 Br, 195 Pt
2
2
12
12
22
35
78
Ans: 2&1, 2&2, 12&12, 12&13, 22&26, 35&44, 78&117
4.0 Write the appropriate symbol for each of the following isotopes: (a) Z = 11, A = 23;
(b) Z = 28, A = 64.
Ans: Na, Ni
5.0 Identify the following as elements or compounds: NH3, N2, S8, NO, CO, CO2, H2,
SO2.
Ans: Elements – N2, S8, H2; Compounds – NH3, NO, CO, CO2, SO2
6.0 Give the number of protons and electrons in each of the following common ions:
Na+, Ca2+, Al3+, Fe2+, I-, F-, S2-, O2-, and N3-.
Ans:
Ion
Na+ Ca2+ Al3+ Fe2+ I− F− S2− O2− N3−
No. protons 11 20
13 26 53 9 16 8
7
No. electrons 10 18
10 24 54 10 18 10
10
7.0 Write the formulas for the following ionic compounds: (a) sodium oxide, (b) iron
sulfide (containing the Fe2+ ion), (c) cobalt sulfate (containing the Co3+ and SO2-4 ions),
and (d) barium fluoride. (Hint: See Figure 2.11.)
Ans:
(a) Sodium ion has a +1 charge and oxide has a − 2 charge. The correct formula is Na2O.
(b) The iron ion has a +2 charge and sulfide has a − 2 charge. The correct formula is FeS.
(c) The correct formula is Co2(SO4)3
(d) Barium ion has a +2 charge and fluoride has a − 1 charge. The correct formula is BaF2.
8.0 Write the formulas for the following ionic compounds: (a) copper bromide
(containing the Cu+ ion), (b) manganese oxide (containing the Mn3+ ion), (c) mercury
iodide (containing the Hg2+2 ion), and (d) magnesium phosphate (containing the PO3-4
ion). (Hint: See Figure 2.11.)
Ans:
(a) The copper ion has a +1 charge and bromide has a − 1 charge. The correct formula is CuBr.
(b) The manganese ion has a +3 charge and oxide has a − 2 charge. The correct formula is Mn2O3.
(c) We have the Hg22+ ion and iodide (I− ). The correct formula is Hg2I2.
(d) Magnesium ion has a +2 charge and phosphate has a − 3 charge. The correct formula is Mg3(PO4)2.
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Chapter 1: Chemistry: The Study of Change
9.0 Which of the following compounds are likely to be ionic? Which are likely to be
molecular? SiCl4, LiF, BaCl2, B2H6, KCl, C2H4
Ans:
Ionic: LiF, BaCl2, KCl
Molecular: SiCl4, B2H6, C2H4
10.0 Define the following terms: acids, bases, oxoacids, oxoanions, and hydrates.
11.0 Name these compounds: (a) Na2CrO4, (b) K2HPO4, (c) HBr (gas), (d) HBr (in
water), (e) Li2CO3, (f) K2Cr2O7, (g) NH4NO2, (h) PF3, (i) PF5, (j) P4O6, (k) CdI2, (l) SrSO4,
(m) Al(OH)3, (n) Na2CO3 ? 10H2O.
Ans: Sodium cromate, potassium hydrogen phosphate, hydrogen bromide,
hydrobromic acid, lithium carbonate, potassium dichromate, ammonium nitrite,
phosphorous trifluoride, phosphorous pentafluoride, tetraphosphorous
hexaoxide, cadmium iodide, strontium sulfate, aluminum hydroxide, sodium
carbonate deca hydrate
12.0 Write the formulas for the following compounds: (a) rubidium nitrite, (b) potassium
sulfide, (c) sodium hydrogen sulfide, (d) magnesium phosphate, (e) calcium hydrogen
phosphate, (f) potassium dihydrogen phosphate, (g) iodine heptafluoride, (h) ammonium
sulfate, (i) silver perchlorate, (j) boron trichloride.
Ans:
(a) RbNO2 (b) K2S (c) NaHS (d) Mg3(PO4)2 (e) CaHPO4
(f) KH2PO4 (g) IF7 (h) (NH4)2SO4 (i) AgClO4 (j) BCl3
13.0 One isotope of a metallic element has mass number 65 and 35 neutrons in the
nucleus. The cation derived from the isotope has 28 electrons. Write the symbol for this
cation.
Ans: Zn+2
14.0 The following table gives numbers of electrons, protons, and neutrons in atoms or
ions of a number of elements. Answer the following:
(a) Which of the species are neutral?
(b) Which are negatively charged?
(c) Which are positively charged?
(d) What are the conventional symbols for all the species?
Atom or
Ion of
Element
Number of
electrons
Number of
protons
Number of
A
B
C
D
E
F
G
5
10
18
28
36
5
9
5
7
19
30
35
5
9
5
7
20
36
46
6
10
Page 6
Chapter 1: Chemistry: The Study of Change
neutrons
(a) Species with the same number of protons and electrons will be neutral. A, F, G.
(b) Species with more electrons than protons will have a negative charge. B, E.
(c) Species with more protons than electrons will have a positive charge. C, D.
(d) A: 10,5B B: 14, 7N -3 C: 39,19K+ D: 66, 30Zn 2+ E: 81,35Br− F: 11,5B G: 19,9F
15.0 Identify the elements represented by the following symbols and give the number of
protons and neutrons in each case:
(a) Ne, 10 p, 10 n (b) Cu, 29 p, 34 n (c) Ag, 47 p, 60 n
(d) W, 74 p, 108 n (e) Po, 84 p, 119 n (f) Pu, 94 p, 140 n
16.0 What is wrong with the name (in parentheses) for each of the following
compounds:
(a) BaCl2 (barium dichloride),
(b) Fe2O3 [iron(II) oxide],
(c) CsNO2 (cesium nitrate),
(d) Mg(HCO3) 2 [magnesium(II) bicarbonate]
Ans:
(a) This is an ionic compound. Prefixes are not used. The correct name is barium chloride.
(b) Iron has a +3 charge in this compound. The correct name is iron(III) oxide.
(c) NO2− is the nitrite ion. The correct name is cesium nitrite.
(d) Magnesium is an alkaline earth metal, which always has a +2 charge in ionic compounds. The roman
numeral is not necessary. The correct name is magnesium bicarbonate.
17.0 Write the formula of the common ion derived from each of the following:
(a) Li, (b) S, (c) I, (d) N, (e) Al, (f) Cs, (g) Mg
Ans:
(a) Li+, alkali metals always have a +1 charge in ionic compounds
(b) S2−
(c) I− , halogens have a − 1 charge in ionic compounds
(d) N3−
(e) Al3+, aluminum always has a +3 charge in ionic compounds
(f) Cs+, alkali metals always have a +1 charge in ionic compounds
(g) Mg2+, alkaline earth metals always have a +2 charge in ionic compounds.
18.0 For the noble gases (the Group 8A elements), 42He, 2010Ne, 4018Ar, 8436Kr, 13254Xe
(a) determine the number of protons and neutrons in the nucleus of each atom, and
(b) determine the ratio of neutrons to protons in the nucleus of each atom.
Ans:
(a) Isotope
No. Protons
No. Neutrons
He Ne Ar Kr
2 10 18 36
2 10 22 48
Xe
54
78
Page 7
Chapter 1: Chemistry: The Study of Change
(b) neutron/proton ratio 1.00, 1.00, (11:9) 1.22, (4:3) 1.33, (13:9) 1.44
The neutron/proton ratio increases with increasing atomic number.
19.0 Identify each of the following elements:
(a) a halogen whose anion contains 36 electrons, - Br(b) a radioactive noble gas with 86 protons, - Rn
(c) a Group 6A element whose anion contains 36 electrons, - Se-2
(d) an alkali metal cation that contains 36 electrons, - Rb+
(e) a Group 4A cation that contains 80 electrons. – Pb+2
20.0 Some compounds are better known by their common names than by their
systematic chemical names. Give the chemical formulas of the following substances:
(a) dry ice, - Solidified CO2
(b) table salt, - NaCl
(c) laughing gas, - N2O
(d) marble (chalk, limestone)
(e) quicklime, (f) slaked lime,
(g) baking soda, (h) washing soda, (i) gypsum,
(j) milk of magnesia.
Ans:
(a) CO2(s), solid carbon dioxide (f) Ca(OH)2, calcium hydroxide
(b) NaCl, sodium chloride (g) NaHCO3, sodium bicarbonate
(c) N2O, nitrous oxide (h) Na2CO3⋅ 10H2O, sodium carbonate decahydrate
(d) CaCO3, calcium carbonate (i) CaSO4⋅ 2H2O, calcium sulfate dihydrate
(e) CaO, calcium oxide (j) Mg(OH)2, magnesium hydroxide
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Chapter 3: (3 points each)
1. There are two stable isotopes of chlorine: chlorine-35, with a mass of 34.968853 amu;
and chlorine-37, with a mass of 36.965903. Given that the average atomic mass of a
chlorine atom is 35.45 amu, which of the following statements is true? (Section: 3.1)
35
17
Cl , with very little 37
17 Cl.
A)
Chlorine contains almost exclusively of
B)
Chlorine contains more
C)
Chlorine contains roughly equal amounts of
D)
Chlorine contains more
37
17
35
17
Cl than
37
17
Cl.
35
17
Cl and
37
17
Cl.
35
Cl than 17
Cl.
35
E) Chlorine contains almost exclusively of 37
17 Cl, with very little 17 Cl.
Ans: (34.968 amu)(0.7553) + (36.956 amu)(0.2447) = 35.45 amu
Page 8
Chapter 1: Chemistry: The Study of Change
2. If 0.274 moles of a substance weighs 62.5 g, what is the molar mass of the substance, in
units of g/mol? (Section: 3.2)
A)
B)
C)
2.28  102 g/mol
1.71  101 g/mol
4.38  10–3 g/mol
D)
E)
2.17  102 g/mol
none of these
3. One mole of iron (Section: 3.2)
A)
B)
C)
is heavier than one mole of lead (Pb). D)
is 77.0 g of iron.
E)
is 26.0 g of iron.
weighs the same as one mole of lead.
None of the above.
4. Determine the number of moles of aluminum in 96.7 g of Al. (Section: 3.2)
A) 0.279 mol
B) 3.58 mol
C) 7.43 mol
D) 4.21 mol
E) 6.02  1023 mol
5. How many atoms are in 5.54 g of F2? (Section: 3.3)
A)
B)
C)
6.02  1023 atoms
0.146 atoms
0.292 atoms
D)
E)
8.78  1022 atoms
1.76  1023 atoms
6. Which of the following samples contains the greatest number of atoms? (Section: 3.2)
A) 100 g of Pb (0.483 mol)
D) 5 g of He (1.25 mol)
B) 2.0 mole of Ar
E) 20 million O2 molecules
C) 0.1 mole of Fe
7. How many sodium atoms are there in 6.0 g of Na3N? (Section: 3.3)
A) 3.6  1024 atoms
D) 0.217 atoms
B) 4.6  1022 atoms
E) 0.072 atoms
23
C) 1.3  10 atoms
8. What is the mass of 3.00 moles of ethanol, C2H6O? (Section: 3.3)
A) 4.99  10–24 g B) 138 g C) 6.52  10–2 g D) 50 g E) 1.81  1024 g
9. Calculate the molecular mass, in g/mol, of C6H12O6. (Section: 3.3)
Ans: 180g/mol
Page 9
Chapter 1: Chemistry: The Study of Change
10. Calculate the mass of 3.7 moles of Br2. (Section: 3.3)
Ans: 591.2896
11. Calculate the volume of 0.15 mole of Br2. The density of Br2 is 3.12 g/mL. (Section: 3.3)
Ans: 7.683 mL
12. A compound with a percent composition by mass of 87.5% N and 12.5% H was recently
discovered. What is the empirical formula for this compound? (Section: 3.6)
87.5/14 = 6.25, 6.25/6.25 = 1 N
12.5/1 = 12.5, 12.5/6.25 = 2 H
NH2 (the compound must be N2H4, Hydrazine)
13. Calculate the molecular mass of ethylene glycol, C2H6O2, a compound frequently used as
automobile antifreeze. (Section: 3.3)
Ans: 62 amu
14. Calculate the percent composition by mass of sodium in Na2CO3. (Section: 3.5)
Ans: 43.396 %
15. Calculate the percent composition by mass of oxygen in Na2CO3. (Section: 3.5)
Ans: 45.283 %
16. Balance the following chemical equation: (Section: 3.7)
NH3 + H2SO4  (NH4)2SO4
Ans: 2(NH3) + H2SO4  (NH4)2SO4
17. Balance the following chemical equation: (Section: 3.7)
C4H10 + O2  CO2 + H2O
Ans: 2(C4H10) + 13 O2  8 CO2 + 10 H2O
18. Balance the following chemical equation: (Section: 3.7)
C + Fe2O3  Fe + CO
Ans: 3C + Fe2O3  2Fe + 3CO
19. Refer to the (unbalanced) equation CS2 + CaO  CO2 + CaS. How many grams of CaS
are produced if 53 g of CO2 are produced? (Section: 3.8)
Ans: 86.4 g (173.76 172.8 g for balanced eq.)
20. How many grams of silver nitrate are necessary to react completely with 7.000 moles of
copper? (Section: 3.8)
Cu + 2 AgNO3  Cu(NO3 )2 + 2 Ag
Ans:2379 (2377.2)g
21. What is the theoretical yield of PI3 if 48.0 g of I2 are reacted with an excess of
phosphorus according to the following chemical equation? (Section: 3.8)
2P(s) + 3I2(s)  2PI3(s)
Ans:51.9 g
Page 10
Chapter 1: Chemistry: The Study of Change
22. Phosphorus reacts with iodine as shown in the chemical reaction below. What is the
percent yield of the reaction if 28.2 g PI3 is obtained from the reaction of 48.0 g of I2 with
excess phosphorus? (Section: 3.10)
2P(s) + 3I2(s)  2PI3(s)
Ans: 54.3%
23. What is the limiting reagent when 27.0 g of P and 68.0 g of I2 react according to the
following chemical equation? (Section: 3.9)
2P(s) + 3I2(s)  2PI3(s)
Ans: I2
24. Oxidation of a hydrocarbon gave a product composed of carbon, hydrogen, and oxygen.
The product that was purified and sent off for elemental analysis giving the following
mass percents: 68.85% C and 4.95% H. Determine the empirical formula of this
compound. (Section: 3.6)
Ans: C7H6O2
25. Acetylene gas, HCCH(g), can be generated in the laboratory by adding calcium carbide
to excess water, as shown in the following reaction (Section: 3.8)
CaC2(s) + H2O(l)  HCCH(g) + CaO(s)
How many grams of CaC2 would be required to generate 0.20 moles of HCCH(g)?
Ans: 13 (12.8) g of CaC2 would be required
Chapter 4: Reactions in Aqueous Solution
1. Which of the following compounds is a strong electrolyte?
A) H2O B) CH3OH C) CH3CH2OH D) HF E) NaF
Ans: E Category: Easy Section: 4.1
2. Which of the following compounds is a weak electrolyte?
A) HNO3 B) NaNO3 C) HNO2 D) NaNO2 E) NaOH
Ans: C Category: Easy Section: 4.1
3. Which of the following compounds is a strong electrolyte?
A) H2O
D) CH3CH2OH (ethanol)
B) N2
E) KOH
C) CH3COOH (acetic acid)
Ans: E Category: Easy Section: 4.1
4. Which of the following compounds is a weak electrolyte?
A) HCl
D) O2
B) CH3COOH (acetic acid)
E) NaCl
C) C6H12O6 (glucose)
Ans: B Category: Easy Section: 4.1
Page 11
Chapter 1: Chemistry: The Study of Change
5. Which of the following compounds is a nonelectrolyte?
A) NaF
D) NaOH
B) HNO3
E) C6H12O6 (glucose)
C) CH3COOH (acetic acid)
Ans: E Category: Easy Section: 4.1
6. Which of the following is the correct net ionic equation for the reaction that occurs when
solutions of Pb(NO3)2 and NH4Cl are mixed?
A) Pb(NO3)2(aq) + 2NH4Cl(aq)  NH4NO3(aq) + PbCl2(s)
B) Pb2+(aq) + 2Cl–(aq)  PbCl2(s)
C) Pb2+(aq) + 2NO3– (aq) + 2NH 4 (aq) + 2Cl–(aq)  2NH 4 (aq) + 2NO3– (aq) +
PbCl2(s)
D) NH4+(aq)+ NO3– (aq)  2NH4NO3(s)
E) No reaction occurs when the solutions are mixed.
Ans: B Category: Medium Section: 4.2
7. What is the correct formula of the salt formed in the neutralization reaction of
hydrochloric acid with calcium hydroxide?
A) CaO B) CaCl2 C) CaH2 D) CaCl E) CaClH
Ans: B Category: Medium Section: 4.3
8. What is the chemical formula of the salt produced by the neutralization of potassium
hydroxide with sulfuric acid?
A) KSO3 B) K2(SO4)3 C) K2SO4 D) K(SO4)2 E) KSO4
Ans: C Category: Medium Section: 4.3
9. The oxidation number of N in NaNO3 is
A) +6 B) +5 C) +3 D) –3 E) None of the above.
Ans: B Category: Medium Section: 4.4
10. The oxidation number of S in K2SO4 is
A) +6 B) +4 C) +2 D) –1 E) None of the above.
Ans: A Category: Medium Section: 4.4
11. The oxidation number of Mn in KMnO4 is
A) +8 B) +7 C) +5 D) –7 E) –8
Ans: B Category: Medium Section: 4.4
12. The oxidation number of Cr in Cr2O72– is
A) –12 B) –7 C) –2 D) +6 E) +7
Ans: D Category: Medium Section: 4.4
13. The oxidation number of Cl in ClO3– is
A) –1 B) +7 C) +5 D) +3 E) None of the above.
Ans: C Category: Medium Section: 4.4
Page 12
Chapter 1: Chemistry: The Study of Change
14. The oxidation number of N in N2H4 is
A) +4 B) –4 C) +2 D) –2 E) 0
Ans: D Category: Medium Section: 4.4
15. In the following redox reaction
4NH3 + 3Ca(ClO)2  2N2 + 6H2O + 3CaCl2
which element is oxidized and which is reduced?
A) H is oxidized and N is reduced
D) Cl is oxidized and O is reduced
B) N is oxidized and Cl is reduced
E) Cl is oxidized and N is reduced
C) N is oxidized and O is reduced
Ans: B Category: Medium Section: 4.4
16. In the following chemical reaction the oxidizing agent is
5S + 6KNO3 + 2CaCO3  3K2SO4 + 2CaSO4 + CO2 + 3N2
A) S B) N2 C) KNO3 D) CaSO4 E) CaCO3
Ans: C Category: Difficult Section: 4.4
17. Identify the oxidizing agent in the following chemical reaction.
2MnO4– + 5H2SO3  2Mn2+ + 5SO42– + 4H+ + 3H2O
A) MnO4– B) H2SO3 C) Mn2+ D) SO42– E) H+
Ans: A Category: Difficult Section: 4.4
18. Identify the reducing agent in the following chemical reaction.
Cd + NiO2 + 2H2O  Cd(OH)2 + Ni(OH)2
A) Cd B) NiO2 C) H2O D) Cd(OH)2 E) Ni(OH)2
Ans: A Category: Difficult Section: 4.4
19. What element is oxidized in the following chemical reaction?
3Cu + 8HNO3  3Cu(NO3)2 + 2NO + 4H2O
A) Cu B) H C) N D) O E) H2O
Ans: A Category: Medium Section: 4.4
20. What element is oxidized in the following chemical reaction?
NiO2 + Cd + 2H2O  Ni(OH)2 + Cd(OH)2
A) Ni B) Cd C) O D) H E) This is not a redox reaction.
Ans: B Category: Medium Section: 4.4
21. What element is oxidized in the following chemical reaction?
H2SO4 + Cd(OH)2  2H2O + CdSO4
A) H B) S C) O D) Cd E) this is not a redox reaction
Ans: E Category: Medium Section: 4.4
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Chapter 1: Chemistry: The Study of Change
22. What element is reduced in the following chemical reaction?
Cu + 2H2SO4  CuSO4 + SO2 + 2H2O
A) Cu B) H C) S D) O E) H2O
Ans: C Category: Medium Section: 4.4
23. Identify the elements that are oxidized and reduced in the following reaction.
KClO3(aq) + 6HBr(aq)  KCl(aq) + 3Br2(l) + 3H2O(l)
A) Br is oxidized and Cl is reduced
D) O is oxidized and Cl is reduced
B) Cl is oxidized and H is reduced
E) Cl is oxidized and Br is reduced
C) H is oxidized and O is reduced
Ans: A Category: Medium Section: 4.4
24. Which of the following represents a halogen displacement reaction?
A) 2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
B) 2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g)
C) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
D) 2KNO3(s)  2KNO2(s) + O2(g)
E) 2LiOH(aq) + H2SO4(aq)  Li2SO4(aq) + 2H2O(l)
Ans: A Category: Easy Section: 4.4
25. Which of the following represents an acid-base neutralization reaction?
A) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
B) SO2(g) + H2O(l)  H2SO3(g)
C) LiOH(aq) + HNO3(aq)  LiNO3(aq) + H2O(l)
D) 2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
E) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
Ans: C Category: Medium Section: 4.4
26. Which of the following represents a hydrogen displacement reaction?
A) 2C2H6(g) + 7O2(g)  4CO2(g) + 6H2O(l)
B) 2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
C) N2(g) + 3H2(g)  2NH3(g)
D) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
E) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
Ans: E Category: Medium Section: 4.4
27. Identify the following compound as an electrolyte or nonelectrolyte: NaOH.
Ans: electrolyte
Category: Easy Section: 4.1
28. Identify the following compound as an electrolyte or nonelectrolyte: H2SO4.
Ans: electrolyte
Category: Easy Section: 4.1
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Chapter 1: Chemistry: The Study of Change
29. Identify the following compound as an electrolyte or nonelectrolyte: C12H22O11(sucrose).
Ans: nonelectrolyte
Category: Easy Section: 4.1
30. Identify the following compounds as a strong electrolytes, weak electrolytes, or
nonelectrolytes: KNO3, KNO2, HNO3, HNO2,
Ans: KNO3, KNO2, and HNO3 are strong electrolytes; HNO2 is a weak electrolyte.
Category: Medium Section: 4.3
31. Write the net ionic equation for the following reaction. Aqueous iron(III) sulfate is added
to aqueous sodium sulfide to produce solid iron(III) sulfide and aqueous sodium sulfate.
Ans: 2Fe3+(aq) + 3S2– (aq)  Fe2S3(s)
Category: Medium Section: 4.2
32. Determine the oxidation number of each of the elements in Cs2Cr2O7?
Ans: the oxidation number of Cs is +1; the oxidation number of Cr is +6; the oxidation
number of O is –2
Category: Easy Section: 4.4
33. Identify the element being oxidized in the following reaction.
4Al + 3O2  2Al2O3
Ans: Al
Category: Medium Section: 4.4
34. Identify the reducing agent in the following reaction.
4Al + 3O2  2Al2O3
Ans: Al
Category: Medium Section: 4.4
35. Identify the element being oxidized in the following reaction.
2KBr + F2  Br2 + 2KF
Ans: BrCategory: Medium Section: 4.4
36. Identify the oxidizing agent in the following reaction.
2KBr + F2  Br2 + 2KF
Ans: F2
Category: Medium Section: 4.4
37. Identify the reducing agent in the following reaction.
2KBr + F2  Br2 + 2KF
Ans: Br– (or KBr)
Category: Medium Section: 4.4
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Chapter 1: Chemistry: The Study of Change
38. Determine the oxidation number of each of the elements BaNaPO4?
Ans: the oxidation number of Ba +2; the oxidation number of Na is +1; the oxidation
number of P is +5; the oxidation number of O is –2
Category: Easy Section: 4.4
39. Thorium metal is prepared by reacting thorium oxide with calcium.
ThO2 + 2Ca  Th + 2CaO
Which substance is reduced in this process?
Ans: Th4+ is reduced
Category: Medium Section: 4.4
40. Batteries in our cars generate electricity by the following chemical reaction.
Pb + PbO2 + 2H2SO4  2PbSO4 + 2H2O
Which substance is reduced in this process?
Ans: Pb4+
Category: Medium Section: 4.4
41. Batteries in our cars generate electricity by the following chemical reaction.
Pb + PbO2 + 2H2SO4  2PbSO4 + 2H2O
What is the oxidizing agent in this process?
Ans: PbO2
Category: Medium Section: 4.4
42. What is the molarity of a solution that contains 5.0 moles of solute in 2.00 liters of
solution?
Ans: 2.5 M
Category: Easy Section: 4.5
43. What is the molar concentration of chloride ions in a solution prepared by mixing 100.
mL of 2.0 M KCl with 50. mL of a 1.5 M CaCl2 solution?
Ans: 2.3 M
Category: Difficult
44. What volume of concentrated nitric acid (15.0 M) is required to make 100. mL of a 3.0 M
nitric acid solution?
Ans: 20. mL
Category: Medium Section: 4.5
45. During a titration the following data were collected. A 10. mL portion of an unknown
monoprotic acid solution was titrated with 1.0 M NaOH; 40. mL of the base were
required to neutralize the sample. What is the molarity of the acid solution?
Ans: 4.0 M
Category: Medium Section: 4.7
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Chapter 1: Chemistry: The Study of Change
46. During a titration the following data were collected. A 10. mL portion of an unknown
monoprotic acid solution was titrated with 1.0 M NaOH; 40. mL of the base were
required to neutralize the sample. How many moles of acid are present in 2.0 liters of
this unknown solution?
Ans: 8.0 moles
Category: Medium Section: 4.7
47. If 145 grams of potassium nitrate were added to water to make 1,500 mL of solution,
what would be the molarity of the resulting solution?
Ans: 0.956 M
Category: Medium Section: 4.5
48. During a titration the following data were collected. A 50.0 mL portion of an HCl
solution was titrated with 0.500 M NaOH; 200. mL of the base was required to neutralize
the sample. How many grams of HCl are present in 500. mL of this acid solution?
Ans: 36.5 g (Use MiVi = MfVf)
Category: Medium Section: 4.7
49. Which substance is acting as a Brønsted acid in the following reaction?
HSO4– + NH4+  H2SO4 + NH3
Ans: NH4+
Category: Medium Section: 4.3
50. Identify the Brønsted acid in the following reaction.
NH3 + H2O  NH4+ + OH–
Ans: H2O
Category: Medium Section: 4.3
51. Write balanced molecular and net ionic equations for the reaction that would occur
between CaCl2(aq) and Na2CO3(aq). Be sure to include the correct states in your final
equations. If no reaction is expected, write “no reaction.”
Ans: Molecular equation: CaCl2(aq) + Na2CO3(aq)  CaCO3(s) + 2NaCl(aq)
Net ionic equation: Ca2+(aq) + CO32–(aq)  CaCO3(s)
Category: Medium Section: 4.2
52. Write balanced molecular and net ionic equations for the acid-base neutralization reaction
between H3PO4(aq) and Ba(OH)2(aq). Be sure to include the correct states in your final
equations. If no reaction is expected, write “no reaction.”
Ans: Molecular equation: 2H3PO4(aq) + 3Ba(OH)2(aq)  Ba3(PO4)2(s) + 6H2O(l)
Net ionic equation: 2H3PO4(aq) + 3Ba2+(aq) + 6OH–(aq)  Ba3(PO4)2(s) + 6H2O(l)
Category: Difficult Section: 4.3
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Chapter 1: Chemistry: The Study of Change
53. Write balanced molecular and net ionic equations for the reaction that would occur
between Al(s) and Co(NO3)2(aq). Be sure to include the correct states in your final
equations. If no reaction is expected, write “no reaction.”
Ans: Molecular equation: 2Al(s) + 3Co(NO3)2(aq)  2Al(NO3)3(aq) + 3Co(s)
Net ionic equation: 2Al(s) + 3Co2+(aq)  2Al3+(aq) + 3Co(s)
Category: Medium Section: 4.4
54. Write balanced molecular and net ionic equations for the reaction that would occur
between CuCl2(aq) and Pb(s). Be sure to include the correct states in your final equations.
If no reaction is expected, write “no reaction.”
Ans: Molecular equation: CuCl2(aq) + Pb(s)  Cu(s) + PbCl2(s)
Net ionic equation: Cu2+(aq) + 2Cl–(aq) + Pb(s)  Cu(s) + PbCl2(s)
Category: Difficult Section: 4.4
55. Write a balanced molecular equation for the reaction that occurs when aqueous solutions
of potassium iodide and lead(II) nitrate are combined.
Ans: 2KI(aq) + Pb(NO3)2(aq)  PbI2(s) + 2KNO3(aq)
Category: Medium Section: 4.2
56. Sugar dissolves in water, therefore it is a strong electrolyte.
Ans: False Category: Medium Section: 4.1
57. The following reaction is an acid-base neutralization reaction.
H2SO4(aq) + CaBr2(aq)  CaSO4(s) + 2HBr(g)
Ans: False Category: Easy Section: 4.3
58. Hydrogen is oxidized in the following chemical reaction.
H2 + Cl2  2HCl
Ans: True Category: Medium Section: 4.4
59. The following equation is an example of a net ionic equation.
Na+(aq) + Br–(aq) + Ag+(aq) + NO3–(aq)  AgBr(s) + Na+(aq) + NO3–(aq)
Ans: False Category: Medium Section: 4.2
60. A weak acid or a weak base ionizes completely.
Ans: False Category: Medium Section: 4.3
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