When an ideal diatomic gas is heated at constant pressure the fraction of the heat energy supplied which increases the internal energy of the gas is

Question

When an ideal diatomic gas is heated at constant pressure the fraction of the heat energy supplied which increases the internal energy of the gas is (A) (2/5) (B) (3/5) (C) (3/7) (D) (5/7)

Tardigrade Admin · Accepted Answer

Cp=Cv+R For diatomic gas, Cv=(5/2) R, Cp=(7/2)R, Thus 5/2R factor of Cp(7/2R) is used in increasing internal energy or heat supplied to increase internal energy of gas at constant P is =(5/2R/7/2R)=(5/7).

Q. When an ideal diatomic gas is heated at constant pressure the fraction of the heat energy supplied which increases the internal energy of the gas is

$\frac{2}{5}$

$\frac{3}{5}$

$\frac{3}{7}$

$\frac{5}{7}$

$C_{p} = C_{v} + R$
For diatomic gas, $C_{v} = \frac{5}{2} R, C_{p} = \frac{7}{2} R,$
Thus $5/2 R$ factor of $C_{p} (7/2 R)$ is used in increasing internal energy or heat supplied to increase internal energy of gas at constant $P$ is $= \frac{5/2 R}{7/2 R} = \frac{5}{7} .$