Question

One mole of an ideal gas $\left(C_{V} = 20 J K^{- 1} m o l^{- 1}\right)$ initially at STP is heated at constant volume to twice the initial temperature. For the process, W and q will be-

• A. $W=0;q=5.46kJ$
• B. $W=0;q=0$
• C. $W=-5.46kJ;q=5.46kJ$
• D. $W=5.46kJ;q=5.46kJ$

Answer 1

Answer: (A)

$T_{1}=273K$

$T_{2}=2\times 273K$

$\Rightarrow \Delta T=273$

Volume is constant

So, $\Delta V=0$

$W=P\Delta V=P\times 0=0$

$q=nC_{V}\left(\Delta T\right)=20\times 273=5460J=5.46kJ$