1. What is the molarity of a K₂CO₃ solution prepared by dissolving 0.655 mole of K₂CO₃ in enough water to make 372 mL of solution? (Molar Mass of K₂CO₃ = 138.2 g/mole)

A. 0.655 M

B. 0.243 M

C. 0.568 M

D. 0.891 M

E. 1.76 M

2. A 1.00 M solution of NaCl in water would contain:

A. 1.00 g NaCl per 1000.0 g H₂O

B. 1.00 mole NaCl per 1000.0 g solution

C. 1.00 mole NaCl per 1000.0 mL H₂O

D. 1.00 kg NaCl per 1.000 kg H₂O

E. 1.00 mole NaCl per 1000.0 mL solution

3. Which of the following is/are true concerning molality?

A. it is a ratio of the moles of solute to the Liters of solvent in a solution

B. it is a ratio of the moles of solute to the kilograms of solvent in a solution

C. its value is influenced by temperature changes.

D. A and C are true.

E. B and C are true.

4. What is the molarity of Cl^- ions in a solution labeled 0.150 M AlCl₃ (aq)?

A. 0.150 M

B. 0.300 M

C. 0.450 M

D. 0.050 M

E. 0.600 M

5. In a solution prepared from two components, the component of lesser quantity is called the

A. solvent B. solute C. diluent D. mixer E. buffer

6. A saturated solution of (NH₄)₂SO₄ in water contains 78.0 g of (NH₄)₂SO₄ per 100.0 g

of H₂O. What is the molality of (NH₄)₂SO₄ in this solution?

A. 0.780 m

B. 1.69 m

C. 5.91 m

D. 6.83 m

E. 9.70 m7. An aqueous solution is 12.0% MgCl₂ by mass and has a density of 1.11 g/mL. What is

the mole fraction of MgCl₂ in the solution? (Molar Mass of MgCl₂ = 95.2 )

A. 0.126

B. 0.114

C. 0.025

D. 0.592

E. 1.43

8. How many grams of Na₃PO₄ are needed to make 100. mL of 0.500 M Na₃PO₄ (aq)?

(Molar Mass of Na₃PO₄ = 164)

A. 16.4 g

B. 8.20 g

C. 4.10 g

D. 3.28 g

E. 50.0 g

For Questions 9 and 10 use the following information:

155.0 mL of 0.450 M Al₂(SO₄)₃ is diluted to 500 mL in a volumetric flask.

9. What is the concentration of Al₂(SO₄)₃ in the new "dilute" solution?

A. 0.0698 M

B. 0.106 M

C. 0.279 M

D. 0.140 M

E. 1.45 M

10. How many grams of Al are in the new "dilute" solution?

A. 12.1 g

B. 23.9 g

C. 1.88 g

D. 7.52 g

E. 3.77 g

11. An endothermic reaction causes its surroundings to:

A. decrease in temperature

B. increase in temperature

C. decrease in heat capacity

D. increase in heat capacity

E. become more acidic

12. If a chemical change "does work" and "loses heat" when it occurs then

A. DE = 0

B. DE > 0

C. DE < 0

D. it cannot be determined

13. "Energy is neither created nor destroyed" would be one way of stating:

A. Hess's Law

B. The First Law of Thermodynamics

C. The Heat Capacity Principle

D. The Ideal Gas Law

E. The Bryan Hypothesis

14. The change in energy associated with any chemical reaction occuring at constant pressure

is called:

A. the internal energy

B. the enthalpy

C. the specific heat capacity

D. the molar heat capacity

E. the heat of formation

15. If a chemical reaction is performed at constant volume, then

A. no heat is exchanged with the surroundings.

B. no work is done.

C. no energy change will occur.

D. no reaction will occur.

E. the reaction time will be increased.

16. Which of the following represents the standard heat of formation reaction for H₂CO₃ (aq) ?

A. H₂CO₃ (aq) ----> H₂ (g) + C (s) + O₂

B. 2 H₂ (g) + 2 C (s) + 3 O₂ (g) ----> 2 H₂CO₃ (aq)

C. H₂O (l) + CO₂ (g) ----> H₂CO₃ (aq)

D. H₂CO₃ (aq) ----> H₂O (l) + CO₂ (g)

E. H₂ (g) + C (s) + O₂ ----> H₂CO₃ (aq)

17. A metal block (T_block = 11°C) placed into beaker of water (T_water = 50°C). Which of the

following is TRUE concerning the resulting exchange of energy?

A. The metal block experiences a decrease in temperature.

B. Heat flows from the metal block into the water.

C. The water experiences an increase in temperature

D. DT for the water will be large because it has a large heat capacity..

E. None of these are true.

18. If a block of nickel has a molar heat capacity of 25.8 J/mol°C, what is its specific heat capacity?

A. 1.5 x 10³ J/g°C

B. 4.4 x 10^-1 J/g°C

C. 3.9x 10^-2 J/g°C

D. 6.17 J/g°C

E. 4.18 J/g°C

19. How much heat is required to raise the temperature of 170. mL of liquid water from

25°C to 100° C?

A. 53.3 kJ

B. 187 kJ

C. 711 kJ

D. 314 J

E. 170 kJ

20. Which of the following substances would most likely have a DH_f° = 0 ?

A. NO₂ (g) B. H₂O (g) C. H₂(g) D. O₃ (g) E. none of these

21. Given the following chemical reaction:

P₄ (s) + 6 Cl₂ (g) ------> 4 PCl₃ (g) , DH_rxn = -1225 kJ

How much energy is released when 0.352 moles of PCl₃ (g) is formed by this reaction?

A. 108 kJ

B. 216 kJ

C. 431 kJ

D. 1720 kJ

E. 3480 kJ

22. Given the following reactions:

C (s) + O₂ (g) -----> CO₂ (l), DH₁ = -394 kJ

S (s) + O₂ (g) -----> SO₂ (g), DH₂ = -296 kJ

CS₂ (l) + 3O₂ (g) -----> CO₂(g) + 2SO₂ (g) , DH₃ = -1072 kJ

Calculate the DH_rxn for the reaction, C(s) + 2 S (s) -----> CS₂ (l) .

A. +874 kJ

B. -1762 kJ

C. +382 kJ

D. +1762 kJ

E. +86 kJ

23. Given the following information:

CO₂ (g) + 2 HCl (g) ------> COCl₂ (g) + H₂O (l) , DH_rxn = ?

Substance	DHf° (kJ)
CO2 (g)	-394
HCl (g)	-92
COCl2 (g)	-223
H2O (l)	-286

Calculate DH_rxn for the reaction above:

A. -995 kJ

B. +23 kJ

C. -23 kJ

D. +69 kJ

E. -299 kJ

24. Given: 2 H₂ (g) + O₂ (g) -----> 2 H₂O (l) , DH_rxn = -572 kJ

What is DH_rxn for the chemical reaction: 4 H₂O (l) -----> 4 H₂ (g) + 2 O₂ (g) ?

A. -572 kJ

B. +572 kJ

C. -1144 kJ

D. +1144 kJ

E. +2288 kJ

25. Which of the following reactions will "do work on their surroundings"?

A. CO₂ (g) + 2 HCl (g) ------> COCl₂ (g) + H₂O (l)

B. P₄ (s) + 6 Cl₂ (g) ------> 4 PCl₃ (g)

C. NH₄NO₃ (s) -----> NH₄⁺ (aq) + NO₃^- (aq)

D. Both A and B

E. None of these

For questions 26 and 27 use the following reaction:

NH₄NO₃ (s) -----> NH₄⁺ (aq) + NO₃^- (aq) DH_soln = +26.2 kJ

26. The reaction shown above could be described as

A. exothermic

B. endothermic

C. a heat of formation reaction

D. a combustion reaction

E. none of the above

27. If 0.586 moles of NH₄NO₃ is dissolved in 155 g of H₂O (l) which is at a temperature of

33.0 °C, what will its final temperature be?

A. 23.7 °C

B. 56.7 °C

C. 9.3 °C

D. 19.3 °C

E. 32.9 °C