An open vessel containing air at 292 K was cooled to a certain temperature at which the number of moles of the gaseous molecules increased by 25%. The final temperature of the vessel is

Suppose the volume of the container is V containing n moles at 292K. Let the temperature be T( K) when, n mole increase to 1.25 n (i.e. by 25%)∵ 1.25 n moles at f (K) occupy a volume, V∵n moles at T( K) occupy a volume V1.25T1=292 K,V1=V,p1=p,  T2=T K,V2=V1.25p1=p2       (constant)From    p1V1T1=p2V2T2pV292=p×V1.25T⇒T=233.6 K≈234 K