Question

In an isobaric process, the ratio of heat supplied to the system ($dq$) and work done by the system ($dW$) for diatomic gas is

• A. 1 : 1
• B. 7 : 2
• C. 7 : 5
• D. 5 : 7

Answer 1

The correct option is B 7 : 2

At constant pressure (isobaric process) heat supplied is given as:
$q_p=n{C}_{p}dT$
$C_p$ for diatomic gas = $\frac{7}{2}R$
so $q_p=\frac{7}{2}nRdT$
work done by system is given as:
$dw=nRdT$
hence the ratio is $\frac{dq}{dw}=\frac{\left(7/2\right)nRdT}{nRdT}$
$=\frac{7}{2}$