Question

One mole of an ideal gas for which $C_V=\left(3/2\right)R$ is heated reversibly at a constant pressure of $1atm$ from ${25}^{\circ }C$ to ${100}^{\circ }C$. The $△H$ is:

• A. $3.775cal$
• B. $37.256cal$
• C. $372.56cal$
• D. $3725.6cal$

Answer 1

The correct option is C $372.56cal$

At Constant pressure ( isobaric process)

$△H=△E+P△V\left[\begin{array}{cc}PV=RT;& P△V=R△T\\ △E=△C_V\times (T_2-T_1)& \end{array}\right]$
$=\frac{3}{2}R\times 75+R\times 75=75\times \frac{5}{2}$
$=372.56cal$