Question

200 g water is heated from 40⁰C to 60⁰C. Ignoring the slight expansion of water, the change in its internal energy is close to (Given specific heat of water=4184 J/kg/K) :

Answer 1

Since expansion is ignored, work done is zero and hence by first law of thermodynamics, internal energy change equals heat supplied.

ΔU=Q=0.2(4184)(20) J=16.7 kJ

Hence, the answer is 16.7 kJ