Chem 1331 Midterm 2

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1.| |
 | What is the pressure, in atm, of a tank of gas with a regulator that reads 1250mmHg? | |
 | Student Response| Correct Answer|
A. | 1.64|   |
B. | 490|   |
C. | 1.79|   |
D. | 0.608|   |
E. | 1.25|   |
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Score:| 0/1 |
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2.| |
 | A 147.9-L sample of dry air is cooled from 88.0°C to 22.1°C while the pressure is maintained at 2.85 atm.

What is the final volume in L? (Do not type the units.) |
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 | Student Response| Correct Answer|
Answer:| not answered  | 120.9|
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Score:| 0/1 |
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3.| |
 | 1000 L of gas is prepared in a tank at 700 mm Hg and 2000 oC. The gas is then transferred to a 40.0 L tank at 200o C. The pressure inside the new tank is | |
 | Student Response| Correct Answer|
A. | 14 mm Hg|   |
B. | 70 mm Hg|   |
C. | 280 mm Hg|   |
D. | 1.75 x 10 3 mm Hg|   |
E. | 3.64 x 103 mm Hg|   |
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Score:| 0/1 |
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4.| |
 | The density of an unknown element in the gaseous state is 1.60 g at 300 K and 1 atm. Which of the following could be the element? | |
 | Student Response| Correct Answer|
A. | He|   |
B. | Ne|   |
C. | Ar|   |
D. | |   |
E. | |   |
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Score:| 0/1 |
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5.| |
 | What is the pressure exerted by a mixture of 0.250 moles of and 0.400 moles of He at 27.0C in a 3.00 L container? | |
 | Student Response| Correct Answer|
A. | 16.0 atm|   |
B. | 5.33 atm|   |
C. | 3.28 atm|   |
D. | 2.05 atm|   |
E. | 1.23 atm|   |
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Score:| 0/1 |
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6.| |
 | At 25°C, an unknown gas, Q, diffuses at a RATE 1.65 times faster than that of propane, C3H8. Which of these gases is most likely to be Q? | |
 | Student Response| Correct Answer|
A. | O2|   |
B. | He|   |
C. | Ne|   |
D. | H2O|   |
E. | CH4|   |
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Score:| 0/1 |
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7.| |
 | In the reaction below, what volume of PCl5 (g) will be produced by the reaction of 69.7 L of chlorine gas with excess phosphorus (P4 if all gas volumes are measured at STP? P4 (g) Cl2 => PCl5 (unbalanced)

Do not enter units with your answer. |
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 | Student Response| Correct Answer|
Answer:| not answered  | 27.9|
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Score:| 0/1 |
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8.| |
 | Consider three 5-L flasks, fitted with pressure gauges and small valves, each contain a gas at 273 K. Flask A contains 4.0 g of H2, flask B contains 4.0 g of He, and flask C contains 8.0 g of CH4. Compare the flasks contents in terms of the characteristics listed.

total kinetic energy of the molecules. |
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 | Student Response| Correct Answer|
A. | Flask A > Flask B > Flask C|   |
B. | Flask A < Flask B < Flask C|   |
C. | Flask A = Flask B = Flask C|   |
D. | Flask A > Flask C > Flask B|   |
E. | Flask C > Flask B > Flask A|   |
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Score:| 0/1 |
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9.| |
 | What is the change in internal energy (in J) of a system that absorbs 4.07 kJ of heat from its surroundings and has 0.66 kcal of work done on it? 1 kcal = 4.184 kJ Express your answer in scientific format with three significant figures: 1.25 x 103 = 1.25E3 Do not type units. | |

 | Student Response| Correct Answer|
Answer:| not answered  | 6.83E3 (6.83 × 103)|
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Score:| 0/1 |
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10.| |
 | If addition of 25.132 kJ of heat to a 0.308 kg sample of an alcohol raises its temperature from 20.00°C to 46.15°C, what is the specific heat capacity of the alcohol in J/g.K? Do not enter units with your answer. | |

 | Student Response| Correct Answer|
Answer:| not answered  | 3.12|
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Score:| 0/1 |
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11.| |
 | Given the following equations:

Determine the enthalpy change (H) for the following reaction:
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 | Student Response| Correct Answer|
A. | 844.3 kJ/mol|   |
B. | 483.3 kJ/mol|   |
C. | -241.7...
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