`1gm` water at `100^(@)C` is heated to convert into steam at `100^(@)C` at `1atm`. Find out chage in internal energy of water. It is given that volume of `1gm` water at `100^(@)C = 1c c`, volume of `1gm` steam at `100^(@)C = 167 1 c c`. Latent heat of vaporization `= 540 cal//g`. (Mechanical equivalent of heat `J = 4.2J//cal)`