Question

volume of 1 mole of steam at 1 atm pressure ​

Answer 1

Answer:

Volume of 0.5 mole of steam at 1 atm pressure

=

P

nRT

=

1.0

0.5×0.0821×373

=15.3L

Change in volume = Vol. of steam − Vol. of water

=15.3− negligible =15.3L

Work done by the system,

w=P

ext

×volumechange

=1×15.3=15.3litre−atm

=15.3×101.3J=1549.89J

w should be negative as the work has been done by the system on the surroundings

w=−1549.89J

Heat required to convert 0.5 mole of water at 100

o

C to steam

=0.5×40670J=20335J

According to the first law of thermodynamics

ΔU=q+w=20335−1549.89=18785.11J