No idea what you are doing, the only thing I am sure about is that it is wrong. 0.0025 is not a mass of KOH, unless you are using some exotic mass units.
What is 0.5?
But it doesn't matter - as I wrote earlier, forget about converting to masses. It doesn't make sense to convert moles to mass, to calculate mass of sulfuric acid from mass of KOH and then to convert mass back to moles, if you can calculate moles of sulfuirc acid directly from moles of KOH.