Question

Universal gas constant is- (a)Cp/Cv (b) Cp – Cv (c) Cp + Cv (d) Cv/Cp.​

Answer 1

Answer:

b) Cp – Cv

Explanation:

Cp = $(\frac{f}{2} +1)R$

Cv = $(\frac{f}{2} )R$

Answer 2

Answer:

$\\\tt C_{p} - C_{v} =R$

Explanation:

It can be proven as followed:

H = U + pV (1st law of thermodynamics)

using Ideal gas law this becomes:

H = U + nRT

For smaller changes:

dH = dU + nR (dT)

dH can be substituted  as $\\\tt n C_{p} dT$ and  dU can be substituted as $\\\tt nC_{v} dT$

Which makes the whole equation:

$\\\tt n C_{p} dT =n C_{v} dT + nR (dT ) \\ \implies C_{p} = C_{v} + R\\\implies C_{p} - C_{v} = R$