Question

The latent hear of vaporization of water is $2240J$. If the work done in the process of vaporization of $1g$ is $168J$, then increase in internal energy is:

• A. $1940J$
• B. $2072J$
• C. $2240J$
• D. $2408J$

Answer 1

Answer: (B)

$2072J$

We know that for first law of thermodynamics, the equation is-

$Q=\Delta E+\Delta W$

Here, $Q=2240;\Delta E=?$ $\Delta W=168$

$\Delta E=Q-\Delta W$

By putting all the values, we get-

$\Delta E=2240-168=2072J$

So, the correct option is $B$