The specific heat of helium at constant volume is 12.6 $\mathrm{Jmol}^{-1} \mathrm{~K}^{-1}$. The specific…
The specific heat of helium at constant volume is 12.6 $\mathrm{Jmol}^{-1} \mathrm{~K}^{-1}$. The specific heat of helium at constant pressure in $\mathrm{Jmol}^{-1} \mathrm{~K}^{-1}$ is about (Assume the temperature of the gas is moderate, universal gas constant, $R=8.314 \mathrm{Jmol}^{-1} \mathrm{~K}^{-1}$ )
$12.6$
$16.8$
$18.9$
$21$
Solution
As $C_V=12.6 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$ is given in SI unit
So, $R=8314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$
Then, $C_p=C_V+R=12.6+8.314=21$