Q 11-12-150JEE MainJEE Main 2019 (12 Apr, Shift 1)Easy
Two moles of helium gas is mixed with three moles of hydrogen molecules (taken to be rigid). What is the molar specific heat of mixture at constant volume? ($R = 8.3$ J/mol K)
Answer: (A) $17.4$ J/mol K
$$C_V = \frac{2\times\frac32R + 3\times\frac52R}{5} = \frac{3R + 7.5R}{5} = 2.1R = 17.4\ \text{J/mol K}$$
Solution by Sreeraj P, M.Sc Physics