1. Which among the following represent a set of isotopes: I. 20 protons and 20 neutrons II. 21 protons and 19 neutrons III. 22 neutrons and 18 protons IV. 20 protons and 22 neutrons V. 21 protons and 20 neutrons.
A) I, II, III B) III, IV C) I, V D) I, IV and II, V E) No isotopes are indicated.
2. The atomic mass of rhenium is 186.2. Given that 37.1% of natural rhenium is rhenium-185, what is the other stable isotope?
A) 183
75
Re B) 187
75
Re C) 189
75
Re D) 181
75
Re E) 190
75
Re
3. For which compound does 0.256 mole weigh 12.9 g?
A) C
2
H
4
O B) CO
2
C) CH
3
Cl D) C
2
H
6
E) C
2
H
4
O
2
4. An oxybromate compound, NaBrO x
, where x is a whole number, is analyzed and found to contain 52.95% Br by mass. What is x?
A) 0 B) 1 C) 2 D) 3 E) 4
5. A mixture of NaCl and NaNO
3
is 31.7% sodium by mass. What is the approximate percent of NaCl in this mixture?
A) 30% B) 32% C) 34% D) 36% E) 38%
6. A 0.4647-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.8635 g of
CO
2
and 0.1767 g of H
2
O. What is the empirical formula of the compound?
A) CHO B) C
2
H
2
O C) C
3
H
3
O
2
D) C
6
H
3
O
2
E) C
3
H
6
O
2
7. When the equation FeCr
2
O
4
+ K
2
CO
3
+ O
2

K
2
CrO
4
+ Fe
2
O
3
+ CO
2
is balanced with the smallest set of integers, the sum of the coefficients is
A) 6 B) 9 C) 15 D) 24 E) 37
8. Consider the following two reactions.
Mg + 2HCl

MgCl
2
+ H
2
2H
2
+ O
2

2H
2
O
How much water (in grams) is produced from 10.0 g of Mg?
A) 1.85 g B) 3.71 g C) 7.41 g D) 18.0 g E) none of these
9. 28.6 g of Al and 17.8 g of Br
2
react according to the following equation:
2Al + 3Br
2

2AlBr
3
What mass of AlBr
3
is formed, assuming 100% yield?
A) 283 g B) 19.8 g C) 29.7 g D) 44.6 g E) 46.4 g
10. A 9.22-g sample of AgNO
3
is reacted with BaCl
2
2AgNO
3
( aq ) + BaCl
2
according to the equation
( aq )

2AgCl( s ) + Ba(NO
3
)
2
( aq ) to give 4.86 g of AgCl. What is the percent yield of AgCl?
A) 44.5% B) 52.7% C) 31.2% D) 62.5% E) 18.7%
11. What volume of 0.450 M barium nitrate solution is needed to prepare 261.0 mL of a solution that is 0.272 M in nitrate?
A) 1.58

10 2 mL B) 7.89

10 1 mL C) 3.16

10 2 mL D) 5.26

10 1 mL E) 4.32

10 2 mL
12. A 6.54-g sample consisting of a mixture of silver nitrate and sodium nitrate is dissolved in water. This aqueous mixture then reacts with aqueous barium chloride to form 3.50 g of silver chloride. Calculate the percent by mass of silver nitrate in the first mixture.
A) 41.5% B) 45.2% C) 77.7% D) 63.4% E) 43.7%
13. Consider the reaction between 50.0 mL of 0.200 M sodium hydroxide and 75.0 mL of 0.100 M HCl. Which of the following statements is correct?
A) After the reaction, the concentration of Na + is greater than the concentration of OH .
B) The NaOH is the limiting reactant.
C) After the reaction, the concentration of Na + is equal to the concentration of Cl .
D) After the reaction, the concentration of Na + is still 0.200 M because Na + is a spectator ion.
E) None of these are correct.
14. Lead(II) nitrate reacts with sodium chloride in aqueous solution to form a precipitate. What is the net ionic equation for this reaction?
A) Pb 2+
B) Na
C) Pb
+
2+
( aq ) + 2NO
( aq ) + Cl
( aq
–
) + 2Cl
3
–
( aq )

Pb(NO
3
( aq )

NaCl( s )
–
( aq )

PbCl
)
2
(s)
D) Na + ( aq ) + NO
3
–
2
( s )
( aq )

NaNO
3
(s)
E) Na + ( aq ) + Cl 2– ( aq )

Na
2
Cl(s)

15. Magnesium metal reacts with hydrochloric acid to form aqueous magnesium chloride and hydrogen gas. When 3.65 g of magnesium is added to 50.0 mL of 3.00 M hydrochloric acid, what mass of hydrogen is produced, assuming a complete reaction?
A) 0.123 g B) 0.151 g C) 0.246 g D) 0.302 g E) none of these
16. When aqueous solutions of silver nitrate and potassium chromate are mixed, the blood-red precipitate silver chromate is formed.
If 10.0 mL of 0.25 M aqueous silver nitrate is mixed with 15.0 mL of 0.14 M aqueous potassium chromate, what is the total concentration of ions in the solution after the precipitate is formed?
A) 0.14 M B) 0.25 M C) 0.30 M D) 0.39 M E) 0.50 M
17. A 0.350-g sample of an acid, HX, requires 25.4 mL of a 0.140 M NaOH solution for complete reaction. Calculate the molar mass of the acid.
A) 42.3 g/mol B) 68.4 g/mol C) 98.4 g/mol D) 121.3 g/mol E) none of these
18. What volume of 0.350 M KOH is required to react completely with 24.0 mL of 0.650 M H
3
PO
4
?
A) 26.0 mL B) 52.0 mL C) 104 mL D) 156 mL E) none of these
19. In which state of the following compounds does nitrogen have the most positive oxidation state?
A) HNO
3
B) NH
4
Cl C) N
2
O D) NO
2
2
5. E
6. C
7. E
8. C
9. B
10. D
11. B
12. D
13. A
14. C
15. B
16. C
17. C
18. E
19. A
20. C
20. Which of the following is(are) oxidation-reduction reactions?
I.
II.
III.
IV.
PCl
3
+ Cl
2

PCl
5
Cu + 2AgNO
3

Cu(NO
3
)
2
+ 2Ag
CO
2
+ 2LiOH

Li
2
CO
3
+ H
2
O
FeCl
2
+ 2NaOH

Fe(OH)
2
+ 2NaCl
A) III only
B) IV only
C) I and II only
D) I, II, and III only
E) I, II, III, and IV
21. Identify the oxidizing and reducing agents for the following reaction: 3 NO
3
(aq) + 8 Cr 3+ (aq) + 19 H
2
O

4 Cr
2
O
7
2(aq) + 3
NH
4
+ (aq) + 26 H + (aq)
A) Cr
2
O
7
2 is the oxidizing agent and NH
4
+
B) Cr
2
O
7
2 is the oxidizing agent and Cr
is the reducing agent
3+ is the reducing agent
C) NO
3
- is the oxidizing agent and NH
4
+ is the reducing agent
D) NO
3
is the oxidizing agent and Cr 3+ is the reducing agent
F) Cr 3+ is the oxidizing agent and NO
3
is the reducing agent
22. Hydrofluoric acid solution reacts with calcium hydroxide solution. What is the net ionic equation for this reaction?
Answer Key
1. D
2. B
3. C
4. D
21. D
22. HF(aq) + OH (aq)

H
2
O(l) + F (aq)