Chem 1331 Midterm 2 Free Essays

1. | | | What is the pressure, in atm, of a tank of gas with a regulator that reads 1250mmHg? | | | Student Response| Correct Answer| A. | 1. We will write a custom essay sample on Chem 1331 Midterm 2 or any similar topic only for you Order Now 64|    | B. | 490|    | C. | 1. 79|    | D. | 0. 608|    | E. | 1. 25|    | | Score:| 0/1 | | | 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. ) | | | Student Response| Correct Answer| Answer:| not answered  Ã‚  | 120. 9| | Score:| 0/1 | | | 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. 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|    | | Score:| 0/1 | | | 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. | |    | | Score:| 0/1 | | | 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|    | | Score:| 0/1 | | | 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|    | | Score:| 0/1 | | | 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. | | | Student Response| Correct Answer| Answer:| not answered  Ã‚  | 27. 9| | Score:| 0/1 | | | 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. | | | 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|    | | Score:| 0/1 | | | 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  Ã‚  | 6. 83E3 (6. 83 ? 103)| | Score:| 0/1 | | | 10. | | | If addition of 25. 132 kJ of heat to a 0. 308 kg sample of an alcohol raises its temperature from 20. 0 °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  Ã‚  | 3. 12| | Score:| 0/1 | | | 11. | | | Given the following equations: Determine the enthalpy change (H) for the following reaction: | | | Student Response| Correct Answer| A. | 844. 3 kJ/mol|    | B. | 483. 3 kJ/mol|    | C. | -241. 7 kJ/mol|    | D. | -483. 3 kJ/mol|    | E. | -844. 3 kJ/mol|    | | Score:| 0/1 | | | 12. | | | High-purity benzoic acid (C6H5COOH; ? Hcomb = –3227 kJ/mol) is a combustion standard for calibrating bomb calorimeters. A 1. 113 g sample burns in a calorimeter (heat capacity of calorimeter alone = 1365 J/ °C) that contains exactly 1. 200 kg of water. What temperature change will be observed? | | | Student Response| Correct Answer| Answer:| not answered  Ã‚  | 4. 60| | Score:| 0/1 | | | 13. | | | Using information from the text Appendix, calculate ? H for the reaction. 2C2H6(g) + 7O2(g) = 4CO2(g) + 6H2O(g) | | | Student Response| Correct Answer| A. | 2855. 4 kJ|    | B. | –2855. 4 kJ|    | C. | 551 kJ|    | D. | –551 kJ|    | E. | None of these is within 5% of the correct answer|    | | Score:| 0/1 | | | 14. | | What mass of (g) must be burned to release 334 kJ of heat to the surroundings? | | | Student Response| Correct Answer| A. | 0. 426 g|    | B. | 6. 00 g|    | C. | 0. 375 g|    | D. | 2. 66 g|    | E. | 55. 6 g|    | | Score:| 0/1 | | | 15. | | | An AM radio station broadcasts at about 1,031 on the radio dial. Units for AM frequencies are given in kilohert z (kHz). What is the wavelength of these radio transmissions in meters (m)? Type only the number. | | | Student Response| Correct Answer| Answer:| not answered  Ã‚  | 291| | Score:| 0/1 | | | 16. | | | A microwave photon has a frequency of 4,561 MHz. What is its energy in joules? Enter your answer in the form 1. 02E12 for 1. 02 x 1012 with three significant figures. Do not enter units with your answer. | | | Student Response| Correct Answer| Answer:| not answered  Ã‚  | 3. 02E-24 (3. 02 ? 10-24)| | Score:| 0/1 | | | 17. | | | What is the frequency (Hz) of a photon emitted by a hydrogen atom when its electron falls from n = 5 to 1? Enter your answer using exponential notation (1. 23 x 104 = 1. 23E4) with three significant figures and do not include units. | | | Student Response| Correct Answer| Answer:| not answered  Ã‚  | 3. 16E15 (3. 16 ? 1015)| | Score:| 0/1 | | | 18. | | Which is not a possible ml value for an orbital that has the following: n = 2 | | | Student Response| Correct Answer| A. | +2|    | B. | –1|    | C. | +1|    | | Score:| 0/1 | | | 19. | | | Give the number of orbitals an atom can have with the following designation: 3p | | | Student Response| Correct Answer| A. | 6|    | B. | 2|    | C. | 3|    | D. | 4|    | E. | an infinite number|    | | Score:| 0/1 | | | 20. | | | Which subatomic particle was found to be present in cathode rays? Type its name only in the box. | | | Student Response| Correct Answer| 1. | not answered  | Equals electron (100%) Equals electrons (100%)| | Score:| 0/1 | | | How to cite Chem 1331 Midterm 2, Essay examples