Question

The total energy of 1 mole of an ideal mono-atomic gas at ${27}^{\circ }C$ is:

• A. 900 cal.
• B. 450 cal.
• C. 1800 cal.
• D. None of these

Answer 1

The correct option is A 900 cal.

$E=\frac{f}{2}RT$

For mono-atomic gases, total no. of the degree of freedom is 3 (translational).

Hence, $f=2$.

$E=\frac{3}{2}RT$ $=\frac{3}{2}\times 2\times 300=900cal$.

Hence, option A is correct