Question

Ideal monoatomic gas is taken through a process $dQ=2dU$. What is the molar heat capacity for the process? ( where dQ is heat supplied and dU is change in internal energy)

• A. 2R
• B. 3R
• C. 4R
• D. 5R

Answer 1

The correct option is B 3R

$dQ=nCpdT$

$Cp-$ heat capacity of constant pressure

$dU=nCvdT$

$Cv-$ heat capacity at constant volume

$n-$ number of moles

$dQ=2dU$

$nCpdT=2nCvdT$

$Cp=2Cv$

$=2\left(\frac{R}{y-1}\right)$

(For mono atomic $y=5/3$ )

$=\frac{2R}{\frac{5}{3}-1}$

$Cp=3R$