Preparation of M/20 oxalic acid solution and determine it strength. For practical

Answer 1

How much do you want to prepare? Say 100 mL. Then
mols oxalic acid needed = M x L = 0.05 M x 0.1 L = ?
Then grams = mols x molar mass = ?

Google how to determine the strength of oxalic acid. The easy way is to titrate it with a standard solution of a base.