1. The problem statement, all variables and given/known data I was given a graph in the PV plane of a cyclic process and asked to find some quantities, one of them is the change in entropy for the system. I just had a question about the units. 2. Relevant equations dS = CVln(Tf/Ti) 3. The attempt at a solution The data was given in Celsius, should I convert to kelvin when I put it into this equation?