Assertion : The increase in internal energy ( E) for the vapourization of one mole of water at 1 ~atm and 373 ~K is zero. Reason : For all isothermal processes, E=0 .

Step-by-step solution

At 373 ~K or 100^ C , the water starts boiling and at this temperature the vaporization of water is an isothermal process. The internal energy change ( E) , depend only on temperature, it follows that at constant temperature, the internal energy of the gas remains constant, i.e. E is zero.