Question

A closed container containing O2 and some liquid H2O was found to exert 740 mm Hg pressure at 27°. Calculate the pressure if (i) volume is reduced to half
(ii) If volume is doubled
also given volume of water is negligible.Aq tension at 27°C=20 mm Hg

Answer 1

Given info : A closed container containing O2 and some liquid H2O was found to exert 740 mm Hg pressure at 27°. and also aqueous tension at 27°C is 20 mm Hg.

To find : the pressure if

1. volume is reduced to half
2. volume is doubled.

solution : pressure of moist gas = pressure of dry gas + aqueous tension

so, pressure of dry gas = pressure of moist gas - aqueous tension

= 740 mm Hg - 20 mm Hg

= 720 mm Hg

now when volume is half at constant temperature, pressure becomes doubled.

so, final pressure of gas = 1440 mm Hg

now pressure = 1440 + 20 = 1460 mm Hg.

Therefore pressure will be 1460 mm Hg.

again, volume is doubled then pressure will be halved.

so, final pressure = 720/2 = 360 mm Hg

now pressure = 360 + 20 = 380mm Hg.

Therefore pressure will be 380 mm Hg.