Question

2 moles of an mono atomic gas undergoes a reversible process for which ${PV}^2=C$. The gas is expanded from initial volume of 1 L to a final volume of 3 L starting from initial temperature of 300 K.

Find $△H$ for te process?

• A. -600 R
• B. -1000 R
• C. -3000 R
• D. -2 k Cal ${mole}^{-1}{K}^{-1}$

Answer 1

Answer: (B)

-1000 R

$P{V}^2=constant$

$\Rightarrow T\times V=constant$

$1\times 300=3\times X$

$\Rightarrow x=100K$

$\Delta H=n{C}_p\Delta T$

$=-2\times \frac{5}{2}R\times 200$ $(\because Cp.\frac{5}{2}R)$

$=-1000R$