Question

The temperature of 5 moles of a gas at constant volume is changed from ${100}^{o}C$ to ${120}^{o}C$. The change in internal energy is 80 J. The Molar heat capacity of the gas at constant volume will be in Joule/Kelvin is

• A. 8
• B. 4
• C. 0.8
• D. 0.4

Answer 1

Answer: (C)

0.8

Change in internal energy in terms of constant volume heat capacity is given by
$\Delta U=n{C}_v\Delta T$
$80=5\left(C_v\right)(120-100)$
$C_v=\frac{80}{\left(5\right)\left(20\right)}=0.8$
Option C.