Question

Calculate the pH of a solution obtained by mixing 25.0 ml of 0.02 M HCl and 50.0 ml of 0.01 M HNO3.

Answer 1

Concentration of mixture = (n1*C1*V1+ n2*C2*V2) / (V1+V2)

where C1 --> Concentration of 1 component

V1-->volume of 1 component

C2 --> Concentration of other component

V2-->volume of other component

n1 --> number of particle from 1 molecule of 1st component

n2 --> number of particle from 1 molecule of 2nd component

use:

[H+] = (n1*C1*V1+ n2*C2*V2) / (V1+V2)

= (1*0.02*25+1*0.01*50)/(25+50)

= 0.0133 M

use:

pH = -log [H+]

= -log (1.33*10^-2)

= 1.8761

Answer: 1.88