Question

Problem 2.2 : The Henry's law constant
of methyl bromide (CH,Br), is 0.159 mol
L'' bar' at 25°C. What is the solubility of
methyl bromide in water at 25°C and at
pressure of 130 mmHg?

Answer 1

Given :- Henery's law constant of CHBr

K = 0.159 mol/(L.atm)

Temperature = 25°C

Partial pressure (P) = 270 am.Hg

To Find:- Solubility (S) of CHBr = ?

Solution:-

- The ability of a substance to dissolve in the solution is called solubility.

- In a liquid Solubility of gas is directly proportional to partial pressure of gas at constant temperature.

- The relation of Solubility with Henry law constant is

Solubility (Concentration) = Henry's law constant (mol/L.atm) × partial pressure (atm)

- Given, Partial pressure of CHBr

= 270 am.Hg

- As we know that,

1 atm = 760 mm.Hg

So, Partial pressure of CHBr will be,

= 270/760 atm

- By putting the value of partial pressure in the above formula we get,

Solubility (Concentration)

= 0.159 × 270/760

= 0.0564 or 5.64 × 10^(-2) mol/L

- Hence, The Solubility of CHBr is

5.64 × 10^(-2) mol/L.