Jose’s lab instructor gives him a solution of sodium phosphate that is buffered to a ph of 4. because of an error that he made while calibrating the ph meter, jose’s measurements of the ph of the sodium phosphate solution are 5.4, 5.4, and 5.4. which statement best describes his results?

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.