1. The problem statement, all variables and given/known data Air is heated from 300 to 350K at constant volume, Find 1Q2. 2. Relevant equations 1Q2 = m(u2-u1)+1W2 u2-u1 = cv(t2-t1) 3. The attempt at a solution The PV diagram of the process is straight up, so the area under the curve is 0, so the work done is zero. Cv is .717 from the back of the book 1Q2 = m*.717(350-300)+0 How do I find the mass? I don't think I'm doing it right.