I am assuming you forgot to include the unit of molarity, M, at the end of 0.500.
Molarity's formula is M=moles solute/liters solution.
We are given molarity and liters so we can rearrange the equation to solve for moles solute. Therefore:
moles solute=molarity * liters solution
moles solute= 0.500M * 0.035L = 0.0175
Thus there are 0.0175 mols of H2SO4 in 0.035L of a 0.500M solution.
