A given mass of an ideal gas is heated in a vessel. The same amount of gas is then heated by keeping it in a larger vessel. Assume that the volumes of both vessel remain the same during heating. What will be the nature of the pressure temperature `(p-T)` graphs in the two cases.

Explanation

In each case the graph is a straight line [Fig.6.16] For a mixed mass of gas,when the volume is less, the pressure increases with temperature at a higher rate.
So the slop of the p-T graph for the smaller container is greater than for the bigger container.
Alternative method:
For a fixed mass of an ideal gas,
`pV=kT or, p=k/V T`.
IF V is fixed,this relation resembles y=mx.
So the p-T graph is a straight line passing through the origin.
Also the slope `k/v` is higher for a smaller V. So the graph of the smaller vessel has a higher slope.