1. The problem statement, all variables and given/known data I have most of these figured out (it is 4 and 5 that are causing me problems) but I figured that I may as well post the answers that I have already gotten because they may be relevant. The answers that I got are in bold. 1. Which of the curves in the figure represents an isothermal process? A. B. C. D. 2. Calculate the change in internal energy DeltaU of the gas as it expands isothermally from V0 to the final volume fvV0. Here, fv is the ratio of final volume to initial volume; fv=4.0 in this problem. DeltaU = 0 3. The pressure, temperature and volume of a system change differently during the process of isothermal expansion. Indicate whether each quantity increases (I), remains constant (C), or decreases (D). Your answers should describe the changes of pressure, temperature, and volume (in that order). Separate your answers with commas (e.g., I,C,D means pressure increases, temperature remains constant, and volume decreases). D,C,I 4. What is the work W done by the gas as it expands isothermally from V0 to fvV0? Express the work done in terms of p0, V0, and fv. Use ln for the natural logarithm. 5. Calculate the quantity of heat Q that must be delivered to the gas as it expands from V0 to fvV0. Express your answer in terms of p0, V0, and fv. Use ln for the natural logarithm. 2. Relevant equations W = p(DeltaV) (At least, I hope so. It was briefly mentioned in lecture). Q = W + (DeltaU) 3. The attempt at a solution 4. Work equals p(DeltaV), so for this problem, I said that W= p0(fvV0-V0). Mastering Physics said that "the answer would be correct if the pressure of the gas remained constant as the volume increased. Use the ideal gas law to determine how the pressure is changing as the volume changes." This confused me. 5. I think that this depends on the answer to number four. I think that it is (ANSWER TO FOUR) + 0.