6.5.5 Molarity and the pH Value of Acid or Alkali

SPM Form 4 Chemistry 6.5 Concentration of Aqueous Solution 6.5.5 Molarity and the pH Value of Acid or Alkali

Molarity and the pH Value of Acid or Alkali

The table below shows the pH value and the molarity of a strong acid and a weak acid.
Molarity of Acids
pH value
Hydrochloric acid
Ethanoic Acid
0.1 mol dm^-3
1.0
2.9
0.01 mol dm^-3
2.0
3.4
0.001 mol dm^-3
3.0
3.9
0.0001 mol dm^-3
4.0
4.4
0.00001 mol dm^-3
5.0
4.9
The table below shows the pH value and the molarity of a strong alkali and a weak alkali.
Molarity of alkali
pH value
Sodium hydroxide solution
Ammonia aqueous
0.1 mol dm^-3
13.0
11.1
0.01 mol dm^-3
12.0
10.6
0.001 mol dm^-3
11.0
10.1
0.0001 mol dm^-3
10.0
9.6
0.00001 mol dm^-3
9.0
9.1
According to the tables shown above, we can conclude that the pH value of acid or alkali is affected by 2 factors:

The Molarity
Strong or weak acid(Alkali)