Question

If $C_P$ and $C_V$ denote the specific heats of nitrogen per unit mass at constant pressure and constant volume respectively, then.

• A. $C_P-C_V=R/28$
• B. $C_P-C_V=R/14$
• C. $C_P-C_V=R$
• D. $C_P-C_V=28R$

Answer 1

Answer: (A)

$C_P-C_V=R/28$

Solution: As we know, molar heat capacity is given by the product of the molar mass and specific heat capacity.

So, at constant pressure and constant volume the molar heat capacities will be $28C_p$ and $28C_v$ respectively (molar mass of nitrogen = 28u).

$\therefore 28C_p-28C_v=R$

or, $C_p-C_v=\frac{R}{28}$

Hence, the correct option is (A).