CHEM 101 Testbank page

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Chem 101 - Final Exam B - Spring, 2000

Problems #1-3 - For the sulfate anion:

1. What is the formula unit?

a) SO3
b) SO42-
c) SO2
d) SO3-

2. What is the AXE notation?

a) AX4E1
b) AX4E0
c) AX3E1
d) AX3E0

3. Predict the electron pair geometry:

a) trigonal bipyramid
b) angular
c) tetrahedral
d) linear

4. VSEPR stands for Valence-Shell Electron Pair Repulsion.

a) True
b) False

5. Balance the following equation:

K3PO4 + BaCl2 ------> Ba3(PO4)2 + KCl

What is the sum of the coefficients?

a) 10
b) 5
c) 12
d) 14

6. What is the coefficient for O2 when the equation: C5H12 + O2 -----> CO2 + H2O is properly balanced?

a) 6
b) 4
c) 8
d) 10

7. What reaction type is represented in Problem #6?

a) oxidation
b) neutralization
c) single-replacement
d) reduction

8. What is the coefficient for O2 when the equation: P + O2 ------> P2O3 is properly balanced?

a) 3
b) 4
c) 2
d) 8

9. What is the molarity of a solution that contains 16.0 grams of H2SO4 in 2.00 liters of water?

a) 0.0408 M
b) 0.0816 M
c) 0.163 M
d) 16.0 M

10. What is the normality of the solution in Problem #9?

a) 0.0408 M
b) 0.0816 M
c) 0.163 M
d) 16.0 M

11. How many milliliters of 0.1025 N NaOH are required to exactly neutralize 50.0 milliliters of 0.2014 N HCl?

a) 98.2 mL
b) 25.4 mL
c) 0.0102 mL
d) 0.201 mL

12. Which ONE of the following is a strong electrolyte?

a) CH3COOH
b) CH3CH2OH
c) CH3OH
d) NaCl

13. How many milliliters of 12.0 M HCl are needed to prepare 5.00 L of 0.500 M HCl?

a) 0.208 mL
b) 208 mL
c) 120 mL
d) 4.80 mL

14. What is the pH of a solution for which [H+] = 2.05 x 10-7 M ?

a) 6.69
b) 2.05 x 10-7
c) 2.05
d) 7.0

15. In CHEM 101 laboratory, the pH of lemon juice was found to be 2.34. What is the hydrogen ion concentration?

a) 0.0457 M
b) 0.00457 M
c) 0.457 M
d) none of these

16. What is the pOH of the lemon juice in Problem #15?

a) 11.66
b) 0.00457
c) 8.50
d) none of these

17. Calculate the sum of the pH and pOH values in Problems #15 and #16. Which of the following expressions is correct?

a) pH + pOH = 14
b) pH + pOH = 7
c) pH = pOH
d) pH + pOH = 0

18. A water solution is considered basic when what is true?

a) [H+] = [OH-]
b) [H+] < [OH-]
c) [H+] > [OH-]

19. Which of the following is most basic?

a) [H+] = 10-4
b) pH = 10
c) [OH-] = 10-3
d) pOH = 12

20. Calculate the pH of a buffer solution which is 4.0 M HF and 4.0 M NaF. Use pKa = 5.0.

a) 4.0
b) 5.0
c) 4.7
d) none of these

21. For Problem #20, which of the following is true?

a) pH > pKa
b) pH < pKa
c) pH = pKa
d) none of these

22. For the electrochemical cell we discussed in class, which of the following occurred?

a) Cu2+ was reduced and deposited on the Cu cathode
b) Zn2+ was reduced and deposited on the Cu cathode
c) Cu2+ was oxidized and deposited on the Zn anode

Problems #23-25 - Classify each of the following half reactions as either (a) oxidation or (b) reduction:

23. 2H+ + 2e- -----> H2(g)

24. Zn (s) ------> Zn2+(aq) + 2e-

25. Cl2(g) + 2e- -----> 2Cl-(aq)

26. What is the element being oxidized for the following redox reaction: 8 H+(aq) + SO42-(aq) + 6 I- (aq) -----> 4 H2O(l) + 3 I2(s) + S(s)

a) S
b) O
c) I-
d) I2

27. In Problem #26, what is the net charge on each side of the reaction equation?

a) 8
b) -2
c) -6
d) 0

28. In Problem #26, is the equation balanced?

a) yes
b) no

29. What is the oxidation number of sulfur in SO42-?

a) 4
b) -2
c) 6
d) 8

30. What is the oxidation number of As in AsO33-?

a) 4
b) 6
c) 3
d) 2

31. What is the oxidation number of Sn in SnO2?

a) 4
b) 6
c) 3
d) 2

32. Which ONE of the following is a correct statement?

a) An increase in oxidation number reflects oxidation.
b) A decrease in oxidation number reflects reduction.
c) A decrease in oxidation number reflects oxidation.
d) none of these

33. Which ONE of the following does NOT describe a property of a gas?

a) Gases may not be compressed.
b) Gases expand to fill their containers.
c) Gases have low density.
d) Gases may be mixed.

34. Which of the following equals one torr unit of pressure?

a) one atmosphere
b) 1 mm Hg
c) 760 mm Hg
d) none of these

35. 250 mL of a gas at 25°C will occupy what volume at 50°C, pressure remaining constant?

a) 271 mL
b) 500 mL
c) 0.00260 mL
d) 250 mL

36. Which of the following correctly shows Charles Law?

37. In the 17th century, Robert Boyle found experimentally that the pressure of a gas is:

a) directly proportional to volume
b) inversely proportional to volume
c) does not depend on volume
d) none of these

38. A container holds 500 mL of gas at 35°C and 780 torr. What will be the volume of the gas if the pressure is increased to 900 torr, the temperature remaining constant?

a) 577 mL
b) 433 mL
c) 463 mL
d) 7.66 mL

39. What would be the volume at STP of 3.62 liters of N2 gas, measured at 649 torr and 16°C?

a) 0 L
b) 7.35 L
c) 3.54 L
d) 2.92 L

KEY

1)b 2)b 3)c 4)a 5)c 6)c 7)a 8)a 9)b 10)c 11)a 12)d 13)b 14)a 15)b 16)a 17)a 18)b 19)c 20)b 21)c 22)a 23)b 24)a 25)b 26)c 27)d 28)a 29)c 30)c 31)a 32)a 33)a 34)b 35)a 36)b 37)b 38)b 39)d
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