A0.5-m3 rigid tank contains refrigerant-134a initially at 200 kpa and 40 percent quality. heat is transferred now to the refrigerant from a source at 35°c until the pressure rises to 400 kpa. determine
(a) the entropy change of the refrigerant
(b) the entropy change of the heat source
(c) the total entropy change for this process

10 kg of co2 is initially contained at 400 kpa and 300 k. the gas constant for carbon dioxide is 189 j/lkg k) and has a specific heat ratio, k, of 1.289. isentropic expansion then occurs until the pressure is 200 kpa. a) determine the initial volume of co2 in m. b) determine the final temperature in k. c) determine the work done by the system during the expansion kl.