Question

With reference to pH scale, (i) Write formula of pH and pOH (ii) Mention pH and concentration of H3O+ or OH- in acidic , basic and netural aqueous solutions. (iii) Mention limitations of pH scale.

Page 152 Chapter - 7.Acids, Bases and Salts

Answer 1

Answer:

(iii) Mention limitations of pH scale.

Answer 2

Dear Student,

◆ Answers with explanation -

(i) pH is negative logarithm to base 10 of hydrogen ion concentration in a solution.

pH = -log[H+]

pOH is negative logarithm to base 10 of hydroxyl ion concentration in a solution.

pH = -log[OH-]

(ii) Acidic solution -

pH < 7

[H3O+] > 10^-7

[OH-] < 10^-7

Basic solution -

pH > 7

[H3O+] < 10^-7

[OH-] > 10^-7

Neutral solution -

pH = 7

[H3O+] = 10^-7

[OH-] = 10^-7

(iii) Limitations of pH scale -

1. pH is useful for only dilute solutions.
2. pH is applicable only for range of 0 to 14.
3. Solution must be aqueous to determine pH.
4. It is affected by change in temperature.

Thanks dear...