How many grams of sulphuric acid will be present in 0.25 mol of sulphuric acid?
( atomic mass of S = 32 u and O = 16 u respectively)

The correct option is C $24.5$
Using mole-mass interconversion,
Number of moles = $\frac{\text{mass}}{\text{molar mass}}$
$\text{Molar mass of sulphuric acid}=2+32+(4\times 16)=98\text{g/mol}$
$\text{Mass}=\text{number of moles}\times \text{molar mass}$
$=0.25\times 98=24.5\text{g}$