Question

If ${\text{C}}_{\text{P}}$ and ${\text{C}}_{\text{V}}$ denote the specific heats of nitrogen per unit mass at constant pressure and constant volume respectively, then

• A. ${\text{C}}_{\text{P}}-{\text{C}}_{\text{V}}=\text{28R}$
• B. ${\text{C}}_{\text{P}}-{\text{C}}_{\text{V}}=\frac{\text{R}}{28}$
• C. ${\text{C}}_{\text{P}}-{\text{C}}_{\text{V}}=\frac{\text{R}}{14}$
• D. ${\text{C}}_{\text{P}}-{\text{C}}_{\text{V}}=\text{R}$

Answer 1

Answer: (B)

Molar heat capacity = Molar mass $\times$ specific heat capacity
So, the molar heat capacities at constant pressure and constant volume will be ${\text{28C}}_{\text{P}}$ and ${\text{28C}}_{\text{V}}$ respectively
$\therefore$ ${\text{28C}}_{\text{P}}-{\text{28C}}_{\text{V}}=\text{R}$ or ${\text{ C}}_{\text{P}}-{\text{C}}_{\text{V}}=\frac{\text{R}}{\text{28}}$ .