A unit mass of an ideal gas at temperature T undergoes a reversible isothermal process from volume V_1 to volume V_2 while losing heat to the surroundings at temperature T in the amouint of q. If the gas constant of the gas is R, what is the entropy change of the gas (Delta_s) during this process?
A) delta s= R ln (V2/V1) -q/T. B) delta s = R ln (V2/V1). C) delta s = R ln (V1/V2). D) delta s = R ln (V1/V2) - q/T. E) delta s= 0.