Chemistry 101 Exam #3 Study Guide—Chapters 9 & 10, Types of Chem. Rxns
Definitions to Know:
 Ionic compound
 Molecular compound
 Combustion Reaction
 Synthesis Reaction
 Decomposition Reaction
 Single-displacement Reaction
 Double-Displacement Reaction
 Cation
 Anion
 Molecular weight
 Molecule
 Formula weight
 Formula unit
Know how to:
 Calculate the empirical formula
 Calculate the molecular formula
 Calculate molecular/formula weight
 Convert grams of an element to moles of an element
 Convert grams of a compound into moles of that compound
 Balance a chemical equation
 Identify the type of chemical reaction
 Give missing reactants or products of a chemical reaction
 Identify the type of compound (ionic or molecular) given the chemical symbol and the Periodic
Table
 Name a molecular compound using the prefix system
 Name an ionic compound using the stock system
 Name the following strong acids and bases
o HF
o HCl
o H2SO4
o HNO3
o HBr
o NaOH
o KOH
o Ba(OH)2
 Be familiar with the more common polyatomic ions—know their names and charges—see page
99 for more info
o Hydroxide ion
o Nitrate ion
o Sulfate ion
o Carbonate ion
o Cyanide ion
o Phosphate ion
o Perchlorate ion
o Ammonium ion
The following questions are practice for you to do. There is no guarantee that the exam will resemble
these problems.
Chemistry 101 Exam #3 Study Guide—Chapters 9 & 10, Types of Chem. Rxns
Practice Problems:
Balance the following equations and list the type of chemical reaction:
1.
2.
3.
4.
5.
6.
Mg + H20 →
Mg(OH)2 + H2
Na2CO3 → Na2O + CO2
HNO3 + ______________ →
Ba(NO3)2 +
C5H12 + _______→ CO2 + H2O
Cu + S8 → CuS
Pb(NO3)2 + HCl → PbCl2 + HNO3
H2O
7. A compound is found to form between As and Br. What is the most likely formula for this compound?
a. AsBr
b. As2Br
c. As2Br3
d. AsBr3
e. As3Br
Answer: D
8. Which combination of atoms would be most likely to produce an ionic bond?
A) Si, C
B) O, Cl
C) Al, F
D) C, H
E) S, Br
Answer: C
9. Calculate to five significant figures, the formula mass of the compound (NH 4)2SO4
A) 132.14
B) 114.10
C) 132.00
D) 114.11
E) 66.138
Answer: A
10. Calculate the formula mass of ammonium nitrite.
a. 64.04
b. 80.04
c. 79.04
d. 63.04
e. 71.847
Answer: A
11. Calculate the formula mass of manganese (IV) oxide.
A) 183.4
B) 86.937
C) 41.00
D) 70.937
E) 235.75
Answer: B
12. Calculate the mass, in grams, of 0.333 mol CO2.
A) 9.33
Chemistry 101 Exam #3 Study Guide—Chapters 9 & 10, Types of Chem. Rxns
B) 12.5
C) 13.3
D) 14.7
E) 44.0
Answer: D
13. Calculate the number of moles of CO present in a 125 g sample of the gas.
A) 2.84
B) 4.46
C) 2.12
D) 8.93
E) 0.224
Answer: B
14. Calculate the number of moles of Ba(OH)2 present in a 100.0 g sample.
A) 0.137
B) 0.171
C) 0.584
D) 0.648
E) 100.
Answer: C
15. Calculate the number of moles of NaCl present in 75.0 g of table salt.
A) 0.643
B) 0.779
C) 28.0
D) 2.56
E) 1.28
Answer: E
16. Calculate the percent of chlorine by mass in PCl3.
A) 22.5
B) 50.0
C) 53.4
D) 25.0
E) 77.4
Answer: E
17. In the compound Na2HPO4 which element is present in the largest percent by mass?
A) Na
B) H
C) P
D) O
E) H and P
Answer: D
18. In the compound Cu2(OH)2CO3, which element is present in the largest percent by mass?
A) Cu
B) O
C) H
D) C
Answer: A
Chemistry 101 Exam #3 Study Guide—Chapters 9 & 10, Types of Chem. Rxns
19. Which of the following cannot be an empirical formula?
A) NO2
B) H2N
C) CH
D) CO2
E) C3H6
Answer: E
20. If the empirical formula of a compound is found to be CH2, which of the following values are plausible
molecular molar masses?
A) 21.04
B) 46.76
C) 12.01
D) 70.15
E) 63.42
Answer: D
21. The empirical formula of the reduced form of lactobionic acid, a sugar used in some medicinal agents, is
CH2O. The molecular mass of this compound is 360. What is the molecular formula?
A) CH2O
B) C360H720O360
C) C19H4O8
D) C12H24O12
E) C16H24O9
Answer: D
22. A 0.100 g sample of a carbon–hydrogen–oxygen compound is combusted in a stream of pure oxygen and
produces 0.220 g CO2 and 0.239 g H2O. What is the mass percent of hydrogen in the sample?
A) 13.3
B) 26.7
C) 60.0
D) 53.2
E) 23.9
Answer: B
23. When the following equation is balanced with lowest ratio whole number coefficients, the coefficient of
CO2 is
C4H10 (g) + O2 (g) → CO2 (g) + H2O (1)
A) 4
B) 5
C) 6
D) 7
E) 8.
Answer: E
24. When the following equation is balanced with lowest ratio whole number coefficients, the coefficient of
CaO is
CaO + P4O10 → Ca3(PO4)2
A) 3
B) 4
C) 5
D) 6
E) 7
Chem 101 Study Guide—Chapters 3 & 4
Tro book
Answer: D
25. When the following equation is balanced, what is the mole ratio of H 2O to Be3N2?
Be3N2 + H2O (l) → Be(OH)2 + NH3 (g)
A) 3/1
B) 3/2
C) 2/3
D) 6/1
E) 1/3
Answer: D
26. When 0.125 mol butane, C4H10, is burned with excess oxygen, ideally how many moles of carbon dioxide
are formed?
2 C4H10 (g) + 13 O2 (g) → 8 CO2 (g) + 10 H2O (l)
A) 0.125
B) 0.500
C) 4.00
D) 1.00
E) 0.250
Answer: B
27. Which name is incorrect?
A) CCl4 carbon tetrachloride
B) N2O4 dinitrogen tetroxide
C) Al2O3 dialuminum trioxide
D) CS2 carbon disulfide
E) SCl2 sulfur dichloride
28. Which name is incorrect?
A) MgS magnesium sulfide
B) FeCl3 iron (III) chloride
C) Ca3N2 calcium nitride
D) Li2O dilithium oxide
E) HBr hydrogen bromide
29. Which of the following compounds is ionic?
A) SF6
B) MgO
C) SOCl2
D) HNO3
E) SeCl2