Question

The temperature of one mole of an ideal gas increases from 298 K when it absorbs 200 J of heat at constant volume. The change in the internal energy of the gas is

• A. 200 J
• B. 140 J
• C. -200 J
• D. - 140 J

Answer 1

Answer: (A)

200 J

Answer 2

Internal energy change is the heat evolved or absorbed at constant volume.
At constant volume; $\Delta V = 0$
Applying, $\Delta U = q + w = q + P\Delta V$
we get, $\Delta U = q =$ 200 J