Question

7 mol of a certain monoatomic ideal gas undergoes a temperature increase of 40 K at constant pressure. The increase in the internal energy of the gas in this process is:
(Given R = 8.3 JK-1 mol-1)

• A. 5810 J
• B. 3486 J
• C. 11620 J
• D. 6972 J

Answer 1

Answer: (B)

3486 J

Answer 2

The increase in the internal energy of the gas,
$△U=nC_v△T$
$△U=7×\frac {3R}{2}×40$
$△U =3486 J$

So, the correct option is (B): $3486\ J$