Chem 1331 Midterm 2

1. What is the pressure, in atm, of a tank of gas with a regulator that reads 1250mmHg? educatee repartee reclaim dish up A. 1. 64 B. 490 C. 1. 79 D. 0. 608 E. 1. 25 micturate 0/1 2. A 147. 9-L sample of dry air is cooled from 88. 0C to 22. 1C while the pressure is maintained at 2. 85 atm. What is the final volume in L? (Do non type the units. ) educatee solution sort out Answer Answer non answered 120. 9 gibe 0/1 3. 1000 L of gas is prep atomic number 18d in a tank at 700 mm Hg and 2000 oC. The gas is whence transferred to a 40. L tank at 200o C. The pressure inside the impertinent tank is learner repartee assort 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 fool 0/1 4. The density of an secret element in the gaseous state is 1. 60 g at 300 K and 1 atm. Which of the followers could be the element? Student solution rectify Answer A. He B. Ne C. Ar D . E. grievance 0/1 5. What is the pressure exerted by a mixture of 0. 250 groines of and 0. four hundred moles of He at 27. 0C in a 3. 00 L container? Student reaction 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 25C, 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 answer 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 friction match (P4 if all gas volumes are measured at STP?P4 (g) Cl2 => PCl5 (unbalanced) Do not enter units with your answer. Student rejoinder Correct Answer Answer not answered 27. 9 Score 0/1 8. Consider terzetto 5-L flasks, fitted with pressure gauges and small valves, each contain a gas at 273 K. flaskful A contain s 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 table of contents in terms of the characteristics listed. total kinetic efficiency of the molecules. Student Response Correct Answer A. flaskful 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 set off from its surroundings and has 0. 66 kcal of work done on it? 1 kcal = 4. 184 kJ distil your answer in scientific format with trey significant figures 1. 25 x 103 = 1. 25E3 Do not type units. Student Response Correct Answer Answer not answered 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. 0C to 46. 15C, what is the specific heat capacity of the alcohol i n J/g. K? Do not enter units with your answer. Student Response Correct Answer Answer not answered 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 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 th e correct answer Score 0/1 14. What mass of (g) must(prenominal) 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 kilohertz (kHz). What is the wavelength of these radio transmissions in meters (m)? Type simply the number. Student Response Correct Answer Answer not answered 291 Score 0/1 16. A microwave photon has a oftenness 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 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 go from n = 5 to 1? Enter your answer using exponentia l function notation (1. 23 x 104 = 1. 23E4) with three significant figures and do not include units. Student Response Correct Answer Answer not answered 3. 16E15 (3. 16 ? 1015) Score 0/1 18. Which is not a contingent 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 ingest 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