Question

Equal masses of methane and ethane have their total translational kinetic energy in the ratio 3 : 1, then their temperatures are in the ratio is

• A. 5: 8
• B. 45: 8
• C. 15: 8
• D. 8: 5

Answer 1

Answer: (D)

$E_{1}=\frac{3}{2}\times \frac{M}{16}RT_{1}$

$E_{2}=\frac{3}{2}\times \frac{M}{30}RT_{2}$

$\Rightarrow \frac{E_{1}}{E_{2}}=\frac{30}{16}\frac{T_{1}}{T_{2}}$

$\Rightarrow \frac{3}{1}=\frac{30}{16}\frac{T_{1}}{T_{2}}$ $\Rightarrow \frac{T_{1}}{T_{2}}=\frac{8}{5}$