Question

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
a) 234 K b) 25 K
c) 210 K d) – 40 K

Answer 1

Answer:

From the ideal gas relation,

PV=nRT

Since the pressure and volume in the given problem is constant, we get

nT=constant

⇒n

1

T

1

=n

2

T

2

⇒T

2

=

1.25

T

1

=

1.25

292

=233.6 K=−39.4

o

C