(a) Here, P & V are constant, n & T are changing. Let, initially the amount of gas present be n & temp is 27oC or 300K. Finally amount of gas present in container =n−23n=(13×n) & final temperature be T.
Then using n1T1=n2T2, we have, n×300=n3×T2⇒T2=900K i.e., final temp =900K
(b) Let there be x moles of gas remaining in the container, 23 of x come out
∴(23x+x)=n⇒5x3=n ∴x=3n5
∴ Using n1 T1=n2 T2 n×300K=3n5×T2
∴T2=500K
Final temperature =500K