Question

4g H2 gas at STP is expanded against
constant pressure 1 atm to twice its
volume. Find the work done :-​

Answer 1

Answer:

Correct option is

D

270 cal

Solution:- (D) 270 cal

At STP, temperature is 273K.

As we know that,

No. of moles (n)=

Mol. wt.

wt.

Given weight =1g

Mol. wt. =2g

∴n=

2

1

=0.5 mole

R=2cal/mol−K

W=PΔV=nRT

W=0.5×2×273=273 cal≈270 cal

Hence the work done will be 270 cal.

As both, temperature and pressure are constant. Hence, we cannot conclude that the process is isothermal or isobaric.