Question

What is the final temperature of $0.10$ mole monoatomic ideal gas that performs $75\text{cal}$ of work adiabatically if the initial temperature is ${227}^{\circ }C?$
(use $R=2{\text{cal K}}^{-1}{\text{mol}}^{-1}$)

• A. $250K$
• B. $300K$
• C. $350K$
• D. $750K$

Answer 1

The correct option is A $250K$

We know $\Delta U=n{C}_{v}dT=n\frac{f}{2}RdT(\because \text{f = Degree of freedom})$
$\Delta U=w$
$\Rightarrow -75=0.1\times \frac{3}{2}\times 2[T_2-500]$
$\Rightarrow T_2=250K$