The equivalent weight of a compound is the molar mass of the compound divided by the number of equivalents of the compound in a reaction.

Oxalic acid has the chemical formula H2C2O4. To find the molar mass, we add up the atomic masses of each element: 2(1.01 g/mol) + 2(12.01 g/mol) + 4(16.00 g/mol) = 90.04 g/mol.

To find the number of equivalents of oxalic acid, we need to look at how it reacts in a specific reaction. In this question, the number of equivalents of oxalic acid is not provided, so we cannot determine the exact value.

However, based on the given options, we can calculate the equivalent weight using the molar mass of oxalic acid. Option 2 states that the equivalent weight is 63. To calculate this value, we divide the molar mass (90.04 g/mol) by the equivalent weight (63): 90.04 g/mol / 63 = 1.43 g/equivalent.

Therefore, according to the given options, the correct answer is option 2: 63. However, it`s important to note that the number of equivalents