Question

One mole of a monoatomic gas and one mole of a diatomic gas are mixed together. What is the molar specific heat at constant volume for the mixture ?

• A. $\frac{5}{2}R$
• B. $2R$
• C. $\frac{3}{2}R$
• D. $3R$

Answer 1

The correct option is B $2R$

Given : One mole of a monoatomic gas and one mole of a diatomic gas are mixed together. What is the molar specific heat at constant volume for the mixture ?

Solution :

$C_{V}mix=\frac{n_1{C}_{V1}+n_2{C}_{V2}}{n_1+n_2}$

We have $n_1=n_2=1mole$ , $C_{V1}=\frac{3R}{2}$ , $C_{V2}=\frac{5R}{2}$

Substituting these values in the formula we get

$C_{V}mix=\frac{\frac{3R}{2}+\frac{5R}{2}}{2}$ = 2R

The Correct Option = B