Question

a. 242 m/s b. 1.21 x 103 m/s c. 822 m/s d. 483 m/s 25. Is this rms speed the same or different from the nitrogen molecules in the sample? Explain. 26. An ideal gas sample of 11 moles initially at STP is isothermally compressed to half its original volume. What must be its final pressure? a. 4.8 atm b. 3 atm c. 2 atm d. 4 atm 27. In the previous question, by what factor does the internal energy of the gas change? 28. An ideal gas sample of 5 moles initially at STP is isobarically expanded to twice its original volume. What must be its final temperature? a. 137 K b. 273 K c. 819 K d. 546 K 29. In the previous question, by what factor does the internal energy of the gas change? 30. Liquids boil when what condition is met involving the vapor pressure: t to the atnaspene presouce 18. A cube of copper (a- 17 x 106/% for copper) with an initial length on each side of 6 cm, is heated (substantially) from 24°C to 215°C, what s the cube's final length at this temperature? What percentage increase is this ,, relative to the initial length? Are you surprised about the percentage? Discuss this.- 1 rroaiy 19. What is the final volume of the copper cube if calculated from the final length? What percentage increase is this in the volume? FAL 20. What is the final volume of the copper cube if calculated using the relationship ß-3a? What percentage increase is this in the volume? Did the percentage increase calculated in this way differ substantially from that calculated in the previous question? oiin't aet time to Study this material nha one week to work on it 21. What is the total internal energy of a sample of 8 moles of air (considered as an ideal gas) at a temperature of 27°C? Assume that the rotational degrees of freedom are fully activated, and that the vibrational modes are "frozen out". a. 1.2 x 105 J b. 4.99 x 104 J c. 7.98 x 104 J d. 9.97 x 104 22. What is the average translational kinetic energy of the oxygen molecules in this sample? (Assume O2 has an atomic mass of 32. Also note that: 1 u- 1.6605x 1027kg. k-1.38 x 10 23 J/K.) a. 9.94 x 10-21 b. 1.8 x 10 20y c. 6.21 x 1021J d. 1.37 x 102J 23. Is this kinetic energy the same or different from the nitrogen molecules in the sample? Explain. 24. What is the rms speed of the oxygen molecules in this sample? What does this speed suggest about the diffusion of odors?

Answer 1

22) Average kinetic energy of diatomic molecules = 3/2 kT

20 6 이. 74, n,e . gaserノdegrees or fe e do… for diak-te 4

2 *1.38 * 10-23 * 300 =

= 6.2 * 10^-21 Jana

23) Since the average kinetic energy depends on temperature only and not on atomic mass, it will be same for Nitrogen molecules

25) since rms speed is inversely proportional to square root of M, and and nitrogen has lower atomic mass than oxygen, nitrogen will have greater rms speed