Calculate the Molar Mass of Oxalic Acid (C = 12, O = 16, H = 1)

Answer: Oxalic Acid: C₂H₂O₄. There are 2 atoms of Carbon, 2 atoms of Hydrogen and 4 atoms of Oxygen. 

So, Molar mass = 12 x 2 + 2 x 1+ 16 x 4

=24+2+64

=90g/mol

Therefore, molar mass of oxalic acid (C₂H₂O₄) = 90g/mol.