Assume the enthalpy of water at 30° c to be 1446 kj while its mass is 8 kg. the average specific heat capacity of is 4.2 kj/kg. k. calculate the enthalpy of water sample at 88 c.

enthalpy of water at is 3394.8 kJ

Explanation:

Mass does not change with change in temperature .

Hence change in enthalpy () during increase in temperature from to is-

where m is mass of water, c is specific heat capacity of water and is change in temperature.

Here, m = 8 kg, c = 4.2 kJ/(kg.K), = (88-30) K = 58 K

So, = 1948.8 kJ

So, enthalpy of water at = enthalpy of water at + = (1446 + 1948.8) kJ = 3394.8 kJ