Question

If pressure of gas collected at water is 715 mm and aqueous tension is 15 mm.What is the

pressure of dry gas?​

Answer 1

Mass of organic substance =0.3 g

Volume of Nitrogen collected =50 mL

Temperature (T

1

)=300 K

Vapour pressure of water =15 mm

Actual pressure of dry nitrogen =715−15=700 mm

At STP, we know that P

2

=760 mm and T

2

=273 K then V

2

=?

⟹

T

1

P

1

V

1

=

T

2

P

2

V

2

⟹

300

700×50

=

273

760×V

2

⟹V

2

=41.9 mL

Hence, % of nitrogen =

22400

28×41.9×100

=5.238%≃6.25