The Carnot efficiency is given by =Tc/Th , where Tc is the temperature of the cold sink and Th is the temperature of the hot sink. True or false? For a heat pump in which heat is extracted from a cold source, some work is done on the engine and thereby converted to heat which is added to that from the cold source before being discarded into the hot sink. The overall change in entropy of a heat pump is S = (qc/Tc)-(qh/Th). True or false? The change in Gibbs free energy is different when the processes occur reversibly and irreversibly. True or false