100 ml of NaHC2O4 required 50 ml of 0.1 M KMnO4 solution in acidic medium.. Volume of 0.1 M NaOH required by 100 ml of NaHC2O4 is......?????

Dear student!

Let us take the reaction as:
NaHC_​2O₄ + KMnO₄---> Mn⁺² + CO2
So, equivalent of NaHC_​2O₄ = equivalent of KMnO₄ 
Since, we know , n_aM_aV_a =n_b​M_bV_​b​ 
By, applying the law we get, molarity of NaHC_​2O₄ as
0.1 x M x 2 = 0.05x 0.1 x 5 
or, M = 0.25/2  = 0.125 
Since, molarity = moles/Volume
Hence, no. of moles = molarity x volume
Further, we have, moles of NaHC_​2O₄ = moles of NaOH
so, 0.125 x 0.1 = 0.1 x V
Hence, V = 0.125 L =125 ml.
Thus, 125 ml of the given NaOH would be required.