The equivalent weight of a substance is the molecular weight divided by the valency. In the case of sulphuric acid (H2SO4), the molecular weight can be calculated by adding up the atomic weights of its constituent atoms, which are H (1) + S (32) + 4O (4 * 16) = 98.

To determine the valency of sulphuric acid, we need to look at the oxidation numbers of each atom. Oxygen has an oxidation number of -2, while hydrogen usually has an oxidation number of +1. Therefore, the oxidation number of sulphur can be calculated by setting up the equation:

2 * x + 4 * (-2) = 0

Simplifying the equation, we get:

2x - 8 = 0

2x = 8

x = 4

Therefore, the valency of sulphur in sulphuric acid is 4.

To find the equivalent weight, we divide the molecular weight (98) by the valency (4):

98 / 4 = 24.5

Therefore, the correct answer is not provided in the options. Alert - The correct answer should be 24.5.