A diatomic gas with rigid molecules does 10 J of work when expanded at constant pressure. What would be the heat energy absorbed by the gas, in this process ?

Question

A diatomic gas with rigid molecules does 10 J of work when expanded at constant pressure. What would be the heat energy absorbed by the gas, in this process ? (A) 35 J (B) 40 J (C) 25 J (D) 30 J

Tardigrade Admin · Accepted Answer

For a diatomic gas, C p =(7/2) R Since gas undergoes isobaric process ⇒ Δ Q=n Cp Δ T Also, Δ W = nR Δ T =10 J ( given ) ∴ Δ Q = n (7/2) R Δ T =(7/2)( nR Δ T )=35 J

Q. A diatomic gas with rigid molecules does $10 J$ of work when expanded at constant pressure. What would be the heat energy absorbed by the gas, in this process ?

35 J

40 J

25 J

30 J

For a diatomic gas, $C_{p} = \frac{7}{2} R$
Since gas undergoes isobaric process $\Rightarrow Δ Q = n C_{p} Δ T$
Also, $Δ W = n R Δ T = 10 J (g i v e n)$
$∴ Δ Q = n \frac{7}{2} R Δ T = \frac{7}{2} (n R Δ T) = 35 J$

Q. A diatomic gas with rigid molecules does 10J of work when expanded at constant pressure. What would be the heat energy absorbed by the gas, in this process ?