The value of the ratio Cₚ/Cᵥ for hydrogen is 1.67 at 30 K but decreases to 1.4 at 300 K as more degrees of freedom become active. During this rise in temperature (assume H₂ as ideal gas),
Options

Question

The value of the ratio Cₚ/Cᵥ for hydrogen is 1.67 at 30 K but decreases to 1.4 at 300 K as more degrees of freedom become active. During this rise in temperature (assume H₂ as ideal gas),

G1 Physics · Accepted Answer

Use PV=nRT, U=(f/2)nRT, γ=1+2/f and vᵣₘₛ=√(3RT/M). At the same temperature, average translational kinetic energy depends only on T. Evaluating the given data/statements gives D: Both Cₚ and Cᵥ increase by the same amount. Therefore the correct answer is D.