1 kg of water at 100°C is converted into steam at 100°C by boiling at atmospheric pressure. The volume of water changes from $1.00\times {10}^{-3}{\mathrm{m}}^3$ as a liquid to $1.671{\mathrm{m}}^3$ as steam. The change in internal energy of the system during the process will be ….. 
(Given latent heat of vaporization = 2257 kJ/kg. Atmospheric pressure = $1\times {10}^5\mathrm{Pa}$ )