Question

During the melting of a slab of ice at 273 K in atmosphere :

• A. positive work is done by the ice - water system on the atmosphere
• B. positive work is done on the ice - water system by the atmosphere
• C. the internal energy of the ice - water increases
• D. the internal energy of the ice - water system decreases

Answer 1

Answer: (B), (C)

The correct options are
B positive work is done on the ice - water system by the atmosphere
C the internal energy of the ice - water increases

During melting, the heat energy is absorbed by the ice-water system from the atmosphere. So positive work is done by atmosphere on the ice-water system, meaning negative work is done by the ice-water system.

Also, the change in the internal energy is $\Delta U=-Workdonebysystem$

As work done by ice-water system is negative, change in internal energy is positive. So the internal energy increases.

So, option B and C are correct.