What is the significance (or importance) of pH value?
The significance of the pH value. pH is a measure of the acidic or basic (alkaline) nature of a solution (concentration of the hydrogen ion [H+] activity in a solution determines the pH).
For neutral solution: pH = 7
For acidic solution: pH < 7
For basic solution: pH > 7
Certain chemical reactions take place at a fixed pH value e.g. fresh cow’s milk (pH = 6·4) turns to the presence of acids produced by the bacteria. The sour milk has a pH 3 to 4.
Calculate the hydrogen ion concentration in the following biological fluids whose pH are given below:
(a) Human muscle-fluid, 6·83
(b) Human stomach fluid, 1·2
(c) Human blood, 7·38
(d) Human saliva, 6·4
The concentration of hydrogen ion in a sample of soft drink is 3·8 × 10-3 M. What is its pH value?