1. A gas absorbs 0.0 J of heat and then performs 30.7 J of work. The change in internal energy of the gas is
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A)
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61.4 J
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B)
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30.7 J
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C)
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-61.4 J
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D)
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-30.7 J
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E)
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none of these
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2. What is the kinetic energy of a 1.56-kg object moving at 94.0 km/hr?
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A)
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5.32 ´ 102 kJ
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B)
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6.89 ´ 103 kJ
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C)
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5.32 ´ 10-4 kJ
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D)
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1.06 ´ 103 kJ
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E)
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2.04 ´ 101 kJ
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3. Which of the following statements correctly describes the signs of q and w for the following exothermic process at P = 1 atm and T = 370 K?
H2O(g) ® H2O(l)
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A)
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q and w are negative.
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B)
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q is positive, w is negative.
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C)
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q is negative, w is positive.
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D)
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q and w are both positive.
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E)
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q and w are both zero.
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4. Which of the following statements is correct?
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A)
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The internal energy of a system increases when more work is done by the system than heat was flowing into the system.
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B)
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The internal energy of a system decreases when work is done on the system and heat is flowing into the system.
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C)
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The system does work on the surroundings when an ideal gas expands against a constant external pressure.
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D)
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All statements are true.
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E)
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All statements are false.
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5. For a particular process q = -17 kJ and w = 21 kJ. Which of the following statements is false?
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A)
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Heat flows from the system to the surroundings.
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B)
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The system does work on the surroundings.
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C)
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DE = +4 kJ
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D)
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The process is exothermic.
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E)
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None of the above is false.
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6. One mole of an ideal gas is expanded from a volume of 1.00 liter to a volume of 8.93 liters against a constant external pressure of 1.00 atm. How much work (in joules) is performed on the surroundings? Ignore significant figures for this problem. (T = 300 K; 1 L·atm = 101.3 J)
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A)
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402 J
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B)
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803 J
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C)
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2.41 ´ 103 J
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D)
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905 J
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E)
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none of these
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7. A fuel-air mixture is placed in a cylinder fitted with a piston. The original volume is 0.310-L. When the mixture is ignited, gases are produced and 935 J of energy is released. To what volume will the gases expand against a constant pressure of 635 mmHg, if all the energy released is converted to work to push the piston?
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A)
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10.7 L
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B)
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8.02 L
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C)
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11.4 L
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D)
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11.0 L
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E)
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1.78 L
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8. Calculate the work associated with the compression of a gas from 121.0 L to 80.0 L at a constant pressure of 13.1 atm.
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A)
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-537 L atm
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B)
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537 L atm
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C)
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3.13 L atm
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D)
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-3.13 L atm
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E)
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101 L atm
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9. A gas absorbs 825 J of heat and then has 841 J of work done upon it. The change in internal energy of the gas is
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A)
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1666 J
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B)
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16 J
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C)
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-16 J
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D)
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-1666 J
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E)
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none of these
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10. Of energy, work, enthalpy, and heat, how many are state functions?
11. Which of the following properties is (are) intensive properties?
I. mass
II. temperature
III. volume
IV. concentration
V. energy
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A)
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I, III, and V
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B)
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II only
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C)
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II and IV
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D)
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III and IV
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E)
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I and V
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12. For the reaction H2O(l) ® H2O(g) at 298 K and 1.0 atm, DH is more positive than DE by 2.5 kJ/mol. This quantity of energy can be considered to be
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A)
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the heat flow required to maintain a constant temperature
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B)
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the work done in pushing back the atmosphere
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C)
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the difference in the H-O bond energy in H2O(l) compared to H2O(g)
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D)
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the value of DH itself
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E)
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none of these
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13. Consider the reaction:
C2H5OH(l) + 3O2(g) ® 2CO2(g) + 3H2O(l); DH = -1.37 ´ 103 kJ
Consider the following propositions:
I. The reaction is endothermic
II. The reaction is exothermic.
III. The enthalpy term would be different if the water formed was gaseous.
Which of these propositions is (are) true?
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A)
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I
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B)
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II
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C)
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III
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D)
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I, II
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E)
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II, III
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14. How much heat is required to raise the temperature of a 5.75-g sample of iron (specific heat = 0.450 J/g°C) from 25.0°C to 79.8°C?
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A)
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2.54 J
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B)
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315 J
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C)
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700 J
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D)
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848 J
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E)
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142 J
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15. A 32.5 g piece of aluminum (which has a molar heat capacity of 24.03 J/°C·mol) is heated to 82.4°C and dropped into a calorimeter containing water (specific heat capacity of water is 4.18 J/g°C) initially at 22.3°C. The final temperature of the water is 24.2°C. Ignoring significant figures, calculate the mass of water in the calorimeter.
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A)
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212 g
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B)
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5.72 kg
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C)
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6.42 g
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D)
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1.68 kg
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E)
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none of these
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16. A 45.9 g sample of a metal is heated to 95.2°C and then placed in a calorimeter containing 120.0 g of water (c = 4.18 J/g°C) at 21.6°C. The final temperature of the water is 24.5°C. Which metal was used?
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A)
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Aluminum (c = 0.89 J/g°C)
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B)
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Iron (c = 0.45 J/g°C)
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C)
|
Copper (c = 0.20 J/g°C)
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D)
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Lead (c = 0.14 J/g°C)
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E)
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none of these
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17. You take 295.5 g of a solid at 30.0°C and let it melt in 425 g of water. The water temperature decreases from 85.1°C to 30.0°C. Calculate the heat of fusion of this solid.
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A)
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160 J/g
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B)
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166 J/g
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C)
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331 J/g
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D)
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721 J/g
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E)
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cannot solve without the heat capacity of the solid
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18. 30.0 mL of pure water at 282 K is mixed with 50.0 mL of pure water at 306 K. What is the final temperature of the mixture?
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A)
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294 K
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B)
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297 K
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C)
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342 K
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D)
|
588 K
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E)
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24 K
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19. Consider the reaction
H2(g) + O2(g) ® H2O(l) DH° = -286 kJ
Which of the following is true?
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A)
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The reaction is exothermic.
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B)
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The reaction is endothermic.
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C)
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The enthalpy of the products is less than that of the reactants.
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D)
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Heat is absorbed by the system.
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E)
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Both A and C are true.
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20. What is the specific heat capacity of a metal if it requires 178.1 J to change the temperature of 15.0 g of the metal from 25.00°C to 32.00°C?
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A)
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0.590 J/g°C
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B)
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11.9 J/g°C
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C)
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25.4 J/g°C
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D)
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1.70 J/g°C
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E)
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283 J/g°C
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21. A 140.0-g sample of water at 25.0°C is mixed with 111.7 g of a certain metal at 100.0°C. After thermal equilibrium is established, the (final) temperature of the mixture is 29.6°C. What is the specific heat capacity of the metal, assuming it is constant over the temperature range concerned?
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A)
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0.34 J/g°C
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B)
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0.68 J/g°C
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C)
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0.22 J/g°C
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D)
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2.9 J/g°C
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E)
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none of these
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22. If 5.0 kJ of energy is added to a 15.5-g sample of water at 10.°C, the water is
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A)
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boiling
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B)
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completely vaporized
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C)
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frozen solid
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D)
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decomposed
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E)
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still a liquid
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23. A chunk of lead at 91.6°C was added to 200.0 g of water at 15.5°C. The specific heat of lead is 0.129 J/g°C, and the specific heat of water is 4.18 J/g°C. When the temperature stabilized, the temperature of the mixture was 17.9°C. Assuming no heat was lost to the surroundings, what was the mass of lead added?
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A)
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1.57 kg
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B)
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170 g
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C)
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204 g
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D)
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211 g
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E)
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none of these
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24. What is the specific heat capacity of silver if it requires 86.3 J to raise the temperature of 15 grams of silver by 25°C?
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A)
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4.3 J/g°C
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B)
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0.23 J/g°C
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C)
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0.14 J/g°C
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D)
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0.60 J/g°C
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E)
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none of these
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25. If a student performs an endothermic reaction in a calorimeter, how does the calculated value of DH differ from the actual value if the heat exchanged with the calorimeter is not taken into account?
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A)
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DHcalc would be more negative because the calorimeter always absorbs heat from the reaction.
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B)
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DHcalc would be less negative because the calorimeter would absorb heat from the reaction.
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C)
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DHcalc would be more positive because the reaction absorbs heat from the calorimeter.
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D)
|
DHcalc would be less positive because the reaction absorbs heat from the calorimeter.
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E)
|
DHcalc would equal the actual value because the calorimeter does not absorb heat.
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26. Consider the reaction: 
When a 21.1-g sample of ethyl alcohol (molar mass = 46.07 g/mol) is burned, how much energy is released as heat?
|
A)
|
0.458 kJ
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B)
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0.627 kJ
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C)
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6.27 ´ 102 kJ
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D)
|
2.89 ´ 104 kJ
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E)
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2.18 kJ
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27. The total volume of hydrogen gas needed to fill the Hindenburg was 2.11 ´ 108 L at 1.00 atm and 24.7°C. How much energy was evolved when it burned?
|
A)
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8.64 ´ 106 kJ
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B)
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2.98 ´ 1010 kJ
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C)
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3.02 ´ 104 kJ
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D)
|
2.47 ´ 109 kJ
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E)
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4.94 ´ 109 kJ
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28. What is the enthalpy change when 49.4 mL of 0.430 M sulfuric acid reacts with 23.3 mL of 0.309 M potassium hydroxide?
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H2SO4(aq) + 2KOH(aq) ® K2SO4(aq) + 2H2O(l)
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DH° = -111.6 kJ/mol
|
|
A)
|
-0.402 kJ
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B)
|
-3.17 kJ
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C)
|
-2.37 kJ
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D)
|
-0.803 kJ
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E)
|
-112 kJ
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29. How much heat is liberated at constant pressure when 2.35 g of potassium metal reacts with 5.68 mL of liquid iodine monochloride (d = 3.24 g/mL)?
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2K(s) + ICl(l) ® KCl(s) + KI(s)
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DH° = -740.71 kJ/mol
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|
A)
|
2.22 ´ 103 kJ
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B)
|
8.40 ´ 101 kJ
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C)
|
1.28 ´ 102 kJ
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D)
|
2.23 ´ 101 kJ
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E)
|
7.41 ´ 102 kJ
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30. Which of the following statements is/are true?
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I. q (heat) is a state function because DH is a state function and q = DH.
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II. When 50.0 g of aluminum at 20.0°C is placed in 50.0 mL of water at 30.0°C, the H2O will undergo a smaller temperature change than the aluminum. (The density of H2O = 1.0 g/mL, specific heat capacity of H2O = 4.18 J/g°C, specific heat capacity of aluminum = 0.89 J/g°C)
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III. When a gas is compressed, the work is negative since the surroundings are doing work on the system and energy flows out of the system.
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IV. For the reaction (at constant pressure) 2N2(g) + 5O2(g) ® 2N2O5(g), the change in enthalpy is the same whether the reaction takes place in one step or in a series of steps.
|
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A)
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I, II, IV
|
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B)
|
II, III
|
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C)
|
II, III, IV
|
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D)
|
II, IV
|
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E)
|
All of the above statements are true.
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31. Consider the following processes:
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2A ® (1/2)B + C
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DH1 = 5 kJ/mol
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(3/2)B + 4C ® 2A + C + 3D
|
DH2 = -15 kJ/mol
|
|
E + 4A ® C
|
DH3 = 10 kJ/mol
|
Calculate DH for: C ® E + 3D
|
A)
|
0 kJ/mol
|
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B)
|
10 kJ/mol
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C)
|
-10 kJ/mol
|
|
D)
|
-20 kJ/mol
|
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E)
|
20 kJ/mol
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32. At 25°C, the following heats of reaction are known:
|
|
DH (kJ/mol)
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|
2ClF + O2 ® Cl2O + F2O
|
167.4
|
|
2ClF3 + 2O2 ® Cl2O + 3F2O
|
341.4
|
|
2F2 + O2 ® 2F2O
|
-43.4
|
At the same temperature, calculate DH for the reaction: ClF + F2 ® ClF3
|
A)
|
-217.5 kJ/mol
|
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B)
|
-130.2 kJ/mol
|
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C)
|
+217.5 kJ/mol
|
|
D)
|
-108.7 kJ/mol
|
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E)
|
none of these
|
33. Given the heats of the following reactions:
|
|
|
DH°(kJ)
|
|
I.
|
P4(s) + 6Cl2(g) ® 4PCl3(g)
|
-1225.6
|
|
II.
|
P4(s) + 5O2(g) ® P4O10(s)
|
-2967.3
|
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III.
|
PCl3(g) + Cl2(g) ® PCl5(g)
|
-84.2
|
|
IV.
|
PCl3(g) + O2(g) ® Cl3PO(g)
|
-285.7
|
Calculate the value of DH° for the reaction below:
P4O10(s) + 6PCl5(g) ® 10Cl3PO(g)
|
A)
|
-110.5 kJ
|
|
B)
|
-610.1 kJ
|
|
C)
|
-2682.2 kJ
|
|
D)
|
-7555.0 kJ
|
|
E)
|
None of these is within 5% of the correct answer.
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34. One of the main advantages of hydrogen as a fuel is that:
|
A)
|
The only product of hydrogen combustion is water.
|
|
B)
|
It exists as a free gas.
|
|
C)
|
It can be economically supplied by the world's oceans.
|
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D)
|
Plants can economically produce the hydrogen needed.
|
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E)
|
It contains a large amount of energy per unit volume of hydrogen gas.
|
35. Consider the following standard heats of formation:
P4O10(s) = -3110 kJ/mol
H2O(l) = -286 kJ/mol
H3PO4(s) = -1279 kJ/mol
Calculate the change in enthalpy for the following process:
P4O10(s) + 6H2O(l) ® 4H3PO4(s)
36. For the complete combustion of 1.000 mole of ethane gas at 298 K and 1 atm pressure, DH° = -1560 kJ/mol. What will be the heat released when 4.42 g of ethane is combusted under these conditions?
|
A)
|
-230 kJ
|
|
B)
|
230 kJ
|
|
C)
|
10588 kJ
|
|
D)
|
-10588 kJ
|
|
E)
|
none of these
|
37. For the complete combustion of 1.000 mole of propane gas at 298 K and 1 atm pressure, DH° = -2220 kJ/mol. What will be the heat released when 4.13 g of propane is combusted under these conditions?
|
A)
|
-208 kJ
|
|
B)
|
208 kJ
|
|
C)
|
23651 kJ
|
|
D)
|
-23651 kJ
|
|
E)
|
none of these
|
38. A 36.2 g piece of metal is heated to 81°C and dropped into a calorimeter containing 50.0 g of water (specific heat capacity of water is 4.18 J/g°C) initially at 21.7°C. The empty calorimeter has a heat capacity of 125 J/K. The final temperature of the water is 29.7°C. Ignoring significant figures, calculate the specific heat of the metal..
|
A)
|
1.439 J/gK
|
|
B)
|
0.900 J/gK
|
|
C)
|
0.360 J/gK
|
|
D)
|
0.968 J/gK
|
|
E)
|
none of these
|