Question

If 'ΔQ' is the amount of heat supplied to 'n' moles of a diatomic gas at constant pressure, 'Δ U' is the change in internal energy and 'Δ W' is the work done, then Δ W : Δ U : Δ Q is ______.

Options

• 1 : 2 : 3

• 2 : 5 : 7

• 2 : 3 : 4

• 5 : 7 : 9

Answer 1

If 'ΔQ' is the amount of heat supplied to 'n' moles of a diatomic gas at constant pressure, 'Δ U' is the change in internal energy and 'Δ W' is the work done, then Δ W : Δ U : Δ Q is 2 : 5 : 7.

Explanation:

We know,

Δ Q = nC_pΔT

Δ U = nC_vΔT

W = P ΔV = nR ΔT

ΔW : ΔU : ΔQ = R : C_v : C_p

For a diatomic gas f = 5

`therefore "C"_"v" = "f"/2 "R" = 5/2 "R"`

C_p = C_v + R = `7/2`R

∴ R : C_v : C_p = 1 : `5/2 : 7/2` = 2 : 5 : 7