1. The problem statement, all variables and given/known data Figure shows two rigid vessels A and B, each of volume 200 cm3 containing an ideal gas (Cv = 12.5 J/mol-K). The vessels are connected to a manometer tube containing mercury. The pressure in both the vessels is 75 cm of mercury and the temperature is 300 . (b) 5.0 J of heat is supplied to the gas in the vessel A and 10 J to the gas in the vessel B. Assuming no appreciable transfer of heat from A to B calculate the difference in the heights of mercury in the two sides of the manometer 2. Relevant equations ΔQ=ΔW+ΔU 3. The attempt at a solution I know that when we give heat to both vessel, the pressure will increase. So the mercury column will also move and there will be a difference in the height in two arms . But my book says when we give heat to vessl there of gas in both vessel will be same. So according to my book ΔW=0 for both vessel. But since mercury will move, one gas should expand and other should compress. Please help me .