Question

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

• A. $\frac{2}{5}$
• B. $\frac{3}{5}$
• C. $\frac{3}{7}$
• D. $\frac{5}{7}$

Answer 1

The correct option is D $\frac{5}{7}$

$Thfractionis\frac{△V}{△Q}=\frac{{}_n{C}_v△T}{{}_n{C}_p△T}\frac{△V}{△Q}=\frac{C_V}{C_P}=\frac{1}{Y}asweknowy=C_P/C_{V}yfordiatomaticgas:C_{P}ofdiatometicgas:\frac{7}{2}{C}_{V}ofdiatometicgas:\frac{5}{2}y=\frac{C_P}{C_V}=\frac{7/2}{5/2}=\frac{7}{5}\frac{△V}{△Q}=\frac{1}{y}=\frac{1}{7/5}=\frac{5}{7}\left(D\right)$