1. The problem statement, all variables and given/known data An ideal monoatomic gas undergoes the following cycle: from 1.) V1 = 1m3, p1=2.5kPa, T1=200k to 2) V2=1m3, p2=7.5kPa then to 3)V3=3m3, p3=2.5kPA, and 4) back to 1). a. Sketch b. How many mole of gas are in the process? c. Give the missing temperatures at positions 2. and 3. d. Find the efficiency of this cycle e. Compare this efficiency with that of a Carnot cycle between the highest and lowest temperatures reached in the above cycle. The transition from 2 → 3 is a linear decrease of the pressure as a function of the volume 2. Relevant equations PV=nRT 3. The attempt at a solution I drew the graph http://imgur.com/7tSPE0k for the first 1 I used n = PV/RT and got 1.5... moles. Now for the second one how should I do it when I have two unknowns. Knowing that from point 1) V1 = 1 and p1 = 2.5 to point 2) pressure changed and there is a linear line going down in the graph the Temperature is not the same in point one. Having two unknowns how to find number of moles in the second part?