Chemistry Unit Review (Pages 332-337) Answers:
Visualizing Key Ideas
1.
Using Key Terms
2. (a) False. Isotopes
(b) False. A basic solution
(c) True
(d) False. an acid with a base
(e) False. single replacement
(f) True
(g) False. catalyst
(h) False. fusion
Checking Concepts
3. (a) Proton, electron, neutron
(b) Proton (1+), electron (1–), neutron (0)
(c) Protons and neutrons are in the nucleus, and electrons surround the nucleus in a regular
pattern.
4. (a)
(b) Boron
5. (a)
(b) Aluminum
6. (a)
(b)
7. (a)
(b)
(c)
(d)
8. Covalent
9. The mass of the reactants is equal to the mass of the products according to the law of
conservation of mass.
10. The pH scale measures the acidity levels in solution.
11. (a) 7
(b) Less than 7
(c) Greater than 7
12. (a) An acid has one or more H on the left side of the formula, as in phosphoric acid (H3PO4).
Organic acids have H on the right side of the formula, as in acetic acid (CH3COOH).
(b) A base has an OH on the right side of the formula and a metal on the left, as in Mg(OH)2.
13. A salt
14. Acid-base indicators
15. (a) 5
(b) 11
(c) 6
16. (a) Yellow
(b) Blue
(c) Green
17. (a) Increased
(b) 10 times
18. (a) Hydrochloric acid, HCl
(b) Sodium hydroxide, NaOH
(c) Sulfuric acid, H2SO4
19. (a) Basic
(b) Acidic
20. (a) The term “organic compound” refers to almost all carbon-containing compounds; exceptions
include carbon dioxide, carbon monoxide, and ionic carbonates, which are considered
inorganic.
(b) The term “inorganic compound” refers to compounds that generally do not contain carbon; the
few exceptions include carbon dioxide, carbon monoxide, and ionic carbonates, which, despite
containing carbon, are considered inorganic.
21. (a) A hydrocarbon is a compound containing the elements carbon and hydrogen.
(b) Methane is used in heating, ethane is used in manufacturing, and propane is used in camp
fuel.
22. Carbon, hydrogen, and oxygen
23. (a) Organic
(b) Inorganic
(c) Inorganic
(d) Organic
(e) Inorganic
(f) Inorganic
(g) Organic
(h) Inorganic
24. (a) Synthesis
(b) Synthesis
(c) Decomposition
(d) Combustion
(e) Neutralization
(f) Neutralization
(g) Double replacement
25. (a) Ca + CuF2  CaF2 + Cu
(b) Rb + O2  Rb2O
(c) C3H7OH+ O2  CO2 + O2
(d) Cl2 + PbI4  PbCl4 + I2
(e) Li2O  Li + O2
(f) HF + Ca(OH)2  CaF2 + H2O
(g) Ba + Ni(NO3)2  Ba(NO3)2 + Ni
(h) Al + I2  AlI2
(i) AgNO3 + Na2CrO4  Ag2CrO4 + NaNO3
26. (a) Temperature
(b) Concentration
(c) Concentration
(d) Catalyst
(e) Surface area
(f) Oxygen (Possibly temperature too, because the flame temperature likely increases. However,
the mixture is given extra oxygen so that the iron in the steel will also oxidize, which is a
concentration effect.)
27. Alpha, beta, and gamma
28. Isotopes are atoms of the same element that differ in the number of neutrons they possess.
29. (a) 11 p
(b) 01 n
(c) 10  ,
(d) 00
0
1
e
(e) 24 , 24 He
30. (a) Both possess eight protons and eight electrons.
(b) Oxygen-16 has eight neutrons, and oxygen-17 has nine neutrons.
31. A beta particle is released from the nucleus of an atom through a process in which a neutron
decays into other particles including a proton and an electron. The electron escapes from the
nucleus as a beta particle. The newly formed proton remains in the nucleus, which increases the
atomic number of the nucleus by one, creating a new element.
32. (a)
(b)
(c)
33.
(d)
34. In a fusion nuclear reaction, small atomic nuclei combine together to form larger ones, typically
with the release of energy. In a fission nuclear reaction, more massive atomic nuclei fragment to
form less massive nuclei.
35. Currently, fission nuclear reactions are used in the generation of electricity and in nuclear
weapons.
Understanding Key Ideas
36. (a) Nickel
(b) Nitrogen
(c) Helium, krypton
(d) Helium, oxygen, chlorine, nitrogen, and krypton
(e) Nickel, tin, sodium, gold
(f) Sodium
37. (a) 4Na + O2  2Na2O
(b) Mg + CuCl2  Cu + MgCl2
(c) CaCO3  CaO + CO2
(d) CrCl3 + 3KOH  3KCl + Cr(OH)3
(e) 2NaCH3COO + Mn(NO3)2  Mn(CH3COO)2 + 2NaNO3
38. Hydrocarbons are compounds that contain both carbon and hydrogen but not other elements.
(a) Hydrocarbon
(b) Not a hydrocarbon due to the presence of oxygen
(c) Hydrocarbon
(d) Not a hydrocarbon due to the presence of calcium and oxygen
(e) Not a hydrocarbon due to the presence of oxygen and the absence of carbon
39. (a) 2NaF  2Na + F2
(b) 6Li+ N2  2Li3N
(c) CH4 + 2O2  CO2 + 2H2O
(d) K2CrO4 + 2AgNO3  2KNO3 + Ag2CrO4
(e) 2LiI + Br2  2LiBr + I2
(f) Cd + I2  CdI2
(g) C3H8 + 5O2  3CO2 + 4H2O
(h) 3MgSO4 + 2In  In2(SO4)3 + 3Mg
(i) AlCl3 + Ru(NO3)3  Al(NO3)3 + RuCl3
(j) H2CO3 + Mg(OH)2  MgCO3 + 2H2O
40. 5 g
41. (a) Greater than 10 million years
(b) 1:1
(c) 1420 million years (the time equivalent to two half-lives)
42. (a) 211
87 Fr
(b)
239
93
(c)
(d)
24
12
232
90
(e)
82
35
(f)
175
78
Np
Mg *
Th
Br
Pt
43. (a)
(b)
(c)
44. (a) Gamma
(b) Beta
(c) Alpha
45. (a) 10 
(b) 00
(c)
162
65
Tb
(d) 
Thinking Critically
46. In a non-metal atom, there are typically more than four valence electrons. In a metal atom, there
are typically fewer than four valence electrons. (Note that for metals, this is more often the case
for the main block elements than for the transition metals.)
47. (a) Accept all logical responses. For example, potassium forms a 1+ ion while fluorine forms a 1–
ion. The formula given would not be electrically neutral, which makes the formula incorrect.
(b) Calcium forms a 2+ ion while bromine forms a 1– ion. The formula given would not be
electrically neutral, which makes the formula incorrect.
(c) Lithium forms a 1– ion while sulphate is a polyatomic ion with a charge of 2–. The formula
given would not be electrically neutral, which makes the formula incorrect.
48. Magnesium reacts to form solid magnesium oxide, which contains all the original magnesium plus
additional mass from the oxygen. Wood burns to form mostly gaseous products such as CO2 and
H2O, which escape, decreasing the mass of the remaining ash.
49. When stuck with a hammer, the ions shift their position so that ions with like charges are adjacent
all along the fracture plane. This causes the entire plane to break away, leaving a flat surface on
both sides of the fracture.
Developing Skills
50. (a) Synthesis, 4Cr + 3O2  2Cr2O3
(b) Single replacement, Cu + 2AgNO3  Cu(NO3)2 + 2Ag
(c) Double replacement, Pb(NO3)2 + 2KI 2KNO3 + PbI2
(d) Combustion, 2C2H6 + 7O2  4CO2 + 6H2O
(e) Decomposition, 2NaCl  2Na + Cl2
(f) Neutralization, HCl + NaOH  NaCl + H2O (balanced)
51. (a) Oxide ion, O2–
(b) Neon atom, Ne
0
1
Applying Your Understanding
52. B
53. C
54. C
55. A
56. B
57. A
58. D
59. D
60. A
61. D
62. B
63. C