Question 691: Thermodynamics & KTG

Question

Heat is given to an ideal gas in an isothermal process. Then
A. internal energy of the gas will decrease.
B. internal energy of the gas will increase.
C. internal energy of the gas will not change.
D. the gas will do negative work.

Accepted Answer

We are dealing with an
isothermal process
for an
ideal gas
.
For an ideal gas, the
internal energy
depends only on its
temperature.
In an isothermal process, temperature remains constant Ã¢ÂÂ
internal energy does not change
(ÃÂU = 0).
Heat supplied to the gas (Q) is completely converted into
work done by the gas
(W).
Therefore: $ Q = W $, and ÃÂU = 0.
Now letÃ¢ÂÂs check the given options:
A. Internal energy of the gas will decrease. Ã¢ÂÂ Ã¢ÂÂ (wrong).
B. Internal energy of the gas will increase. Ã¢ÂÂ Ã¢ÂÂ (wrong).
C. Internal energy of the gas will not change. Ã¢ÂÂ Ã¢ÂÂ (correct).
D. The gas will do negative work. Ã¢ÂÂ Ã¢ÂÂ (since gas does
positive
work when it expands).
Ã¢ÂÂ
Correct Answer: Option B (C: Internal energy of the gas will not change)
Ã¢ÂÂ

Answer

B

Answer

C

Answer

D

Answer

A

Thermodynamics & KTG

Heat is given to an ideal gas in an isothermal process. Then A. internal energy of the gas will decrease. B. internal energy of the gas will increase. C. internal energy of the gas will not change. D. the gas will do negative work.

Choose the correct answer: