1 mole of a gas with γ = 7/5 is mixed with 1 mole of a gas with γ = 5/3, then the value of γ for the resulting mixture is (a) 7/5 (b) 2/5 (c) 3/2 (d) 12/7

Answer: (c). γ = 7/5: CV = 5/2R; γ = 5/3: CV = 3/2R. CVmix = (2.5R + 1.5R)/(2) = 2R, CPmix = 3R γ = 3/2 So the answer is (c) 3/2.

1 mole of a gas with γ = 7/5 is mixed with 1 mole of a gas with γ =… | JEE Main 2002 (AIEEE)

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Specific Heats of Gases - Cp, Cv, γ & Mayer's Relation

1 mole of a gas with $\gamma = 7/5$ is mixed with $1$ mole of a gas with $\gamma = 5/3,$ then the value of $\gamma$ for the resulting mixture is

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Answer: (c)

$\gamma = \dfrac{7}{5}$ : $C_V = \dfrac{5}{2}R$ ; $\gamma = \dfrac{5}{3}$ : $C_V = \dfrac{3}{2}R$ .
$C_V^{mix} = \dfrac{2.5R + 1.5R}{2} = 2R$ , $C_P^{mix} = 3R$
$\gamma = \dfrac{3}{2}$
So the answer is (c) $3/2$ .