Unit 2 Practice Test: Chemical Reactions

1. The following reactions:
	
are examples of

[A] unbalanced reactions.

[B] acid-base reactions.

[C] precipitation, acid-base, and redox reactions, respectively.

[D] redox, acid-base, and precipitation reactions, respectively.

[E] precipitation, redox, and acid-base reactions, respectively.

 You have 75.0 mL of a 2.50 M solution of Na2CrO4(aq).  You also have 125 mL of a 2.50 M solution of AgNO3(aq). Calculate the concentrations of the following ions when the two solutions are added together.

2. NO3-

[A] 3.13 M

[B] 0.313 M

[C] 2.50 M

[D] 0 M

[E] 1.56 M

 You have 75.0 mL of a 2.50 M solution of Na2CrO4(aq).  You also have 125 mL of a 2.50 M solution of AgNO3(aq). Calculate the concentrations of the following ions when the two solutions are added together.

3. Na+

[A] 2.50 M

[B] 1.88 M

[C] 0.938 M

[D] 0 M

[E] 5.00 M

4. Which of the following is paired incorrectly?

[A] HI - strong acid

[B] HBr - strong acid

[C] HNO3 - weak acid

[D] Ba(OH)2 - strong base

[E] NH3 - weak acid

5. The following reactions
	
are examples of

[A] precipitation (two) and acid-base reactions, respectively.

[B] precipitation reactions.

[C] redox, precipitation, and acid-base, respectively.

[D] redox reactions.

[E] none of these

6. Which of the following is a strong acid?

[A] HBrO

[B] HClO

[C] HF

[D] KOH

[E] HClO4

7. In the reaction shown below, what species is oxidized?
	2NaI + Br2 ® 2NaBr + I2

[A] Na+

[B] I2

[C] Br2

[D] Br-

[E] I-

8. Selecting from the following reagents, indicate which reagents would be mixed to give the compounds in the questions below.
	
 Cu(OH)2

9. An acid is a substance that produces OH- ions in water.

[A] True

[B] False

10. You mix 60.0 mL of 1.0 M silver nitrate with 25.0 mL of 0.80 M sodium chloride. What mass of silver chloride should you form?

[A] 5.8 g

[B] 9.6 g

[C] 2.9 g

[D] 8.7 g

[E] none of these

11. When the equation Cl2 ® Cl- + ClO3- (basic solution) is balanced using the smallest whole-number coefficients, the coefficient of OH- is:

[A] 1

[B] 3

[C] 2

[D] 6

[E] 4

12. If all of the chloride in a 5.000-g sample of an unknown metal chloride is precipitated as AgCl with 70.90 mL of 0.2010 M AgNO3, what is the percentage of chloride in the sample?

[A] 20.22%

[B] 10.10%

[C] 50.55%

[D] 1.425%

[E] none of these

13. Aqueous solutions of barium chloride and silver nitrate are mixed to form solid silver chloride and aqueous barium nitrate.
 The balanced molecular equation contains which one of the following terms?

[A] BaNO3

[B] 2AgCl(s)

[C] 3AgCl(s)

[D] 2Ba(NO3)2

[E] AgCl(s)

14. In the reaction C(s) + O2(g) ® CO2(g) carbon is __________.

[A] reduced

[B] the reducing agent

[C] the electron acceptor

[D] the oxidizing agent

[E] more than one of these

15. In the reaction Zn + H2SO4 ® ZnSO4 + H2, which, if any, element is oxidized?

[A] oxygen

[B] zinc

[C] hydrogen

[D] sulfur

[E] none of these

16. Balance each of the following equations.
 Cr2O72- + I- ® Cr3+ + IO3- (acid)

17. What mass of NaOH is required to react exactly with 25.0 mL of 1.2 M H2SO4?

[A] 3.5 g

[B] 2.4 g

[C] 1.2 g

[D] 1.8 g

[E] none of these

18. The following unbalanced equation represents a reaction that occurs in basic solution:
	MnO42- + C2O42- ® MnO2 + CO32-
How many moles of MnO42- are required to produce 1 mole of CO32-?

[A] 4

[B] 1

[C] 2

[D] 3

[E] none of these

19. Which of the following salts is insoluble in water?

[A] Na2S

[B] K3PO4

[C] CaCl2

[D] Pb(NO3)2

[E] All of these are soluble in water.

20. In which of the following does nitrogen have an oxidation state of +4?

[A] NH4Cl

[B] HNO3

[C] NaNO2

[D] N2O

[E] NO2

21. Which of the following is not a strong base?

[A] NH3

[B] Ca(OH)2

[C] LiOH

[D] KOH

[E] Sr(OH)2

22. Soluble ionic compounds containing the hydroxide ion are called strong __________.

23. A 20.0-g sample of HF is dissolved in water to give 2.0 ´ 102 mL of solution. The concentration of the solution is:

[A] 0.10 M

[B] 3.0 M

[C] 10.0 M

[D] 5.0 M

[E] 1.0 M

24. Which of the following statements is(are) true? Oxidation and reduction

[A] cannot occur independently of each other.

[B] accompany all chemical changes.

[C] describe the loss and gain of electron(s), respectively.

[D] result in a change in the oxidation states of the species involved.

[E] a, c, and d are true

25. How many grams of NaOH are contained in 5.0 ´ 102 mL of a 0.80 M sodium hydroxide solution?

[A] 16 g

[B] 80. g

[C] 64 g

[D] 20. g

[E] none of these

26. A 1.000-g sample of a metal chloride, MCl2, is dissolved in water and treated with excess aqueous silver nitrate. The silver chloride that formed weighed 1.286 g. Calculate the atomic mass of M.

[A] 304.0 g

[B] 152.0 g

[C] 76.00 g

[D] 222.8 g

[E]  none of these

27. The concentration of a salt water solution which sits in an open beaker decreases over time.

[A] True

[B] False

Reference: 4.4-9
[1] [E]

Reference: 4.7
[2] [E]

Reference: 4.7
[3] [B]

Reference: 4.2
[4] [C]

Reference: 4.4–9
[5] [C]

Reference: 4.2
[6] [E]

Reference: 4.9
[7] [E]

Reference: 4.5,6
[8] CuSO4(aq) and NH3(aq)

Reference: 4.2
[9] [B]

Reference: 4.7
[10] [C]

Reference: 4.10
[11] [D]

Reference: 4.7
[12] [B]

Reference: 4.5,6
[13] [B]

Reference: 4.9
[14] [B]

Reference: 4.9
[15] [B]

Reference: 4.10
[16] 8H+ + Cr2O72- + I- ® 2Cr3+ + IO3- + 4H2O

Reference: 4.8
[17] [B]

Reference: 4.10
[18] [E]

Reference: 4.5
[19] [E]

Reference: 4.9
[20] [E]

Reference: 4.2
[21] [A]

Reference: 4.1
[22] bases

Reference: 4.3
[23] [D]

Reference: 4.9
[24] [E]

Reference: 4.3
[25] [A]

Reference: 4.7
[26] [B]

Reference: 4.3
[27] [B]