Question

When the temperature of a fixed amount of gas changes from 20 C to 40 C, what happens to the volume at constant pressure?

Answer 1

Usually volume is directy proportional to temperature.

if Temperature increases volume will also increase at constant pressure.

you didn't mention here whether it is real gas or ideal gas. when it is not mentioned we have to consider as ideal gas.

hence for ideal gas

vanderwaal relation

PV = NRT

P - pressure

V - volume

N - no of moles

R - gas constant.

T - Temperature

here Fixed amount of gas ( N constant ), Pressure Constant.

PV₁ / PV₂ = NRT₁ /NRT₂

V₁ / V₂ = T₁ /T₂

V₁ / V₂ = (273+20) K /(273+40) K

V₁ / V₂ = 0.936

V₂ = V₁/ 0.936

V₂ = 1.068 V₁

Considering the gas as ideal if temperature increases from 20 C (293 K) to 40 C (313 K)

volume will increase by a factor of 1.068