Question

1. One mole of oxygen gas is heated from 20°C to 100°C at a pressure of
1 atmosphere. Calculate the amount of heat required during the heating
if (a) volume is kept constant (b) pressure is kept constant, and (c)
What work is done if the pressure is constant, (Assume that oxygen
an ideal gas); (d) increase in its internal energy.
is​

Answer 1

Explanation:

R=8.31Jmol

−1

deg

−1

=

4.18

8.31

cal mol

−1

deg

−1

=1.99cal mol

−1

deg

−1

We know that C

P

−C

V

=R

or C

V

=C

P

−R=7.03−1.99=5.04cal mol

−1

deg

−1

Heat absorbed by 5 mole of oxygen in heating from 10

o

C to 20

o

C

=5×C

V

×ΔT=5×5.04×10=252cal

Since, the gas is heated at constant volume, no external work is done,

i.e., w=0

So, change in internal energy will be equal to heat absorbed,

ΔU=q+w=252+0=252cal