For a 24.832 g sample of p-xylene (C₈H₁₀), the amount of substance is obtained by dividing the sample mass by the molar mass calculated from the standard atomic weights of carbon and hydrogen. Carbon contributes 8 × 12.011 g mol⁻¹ = 96.088 g mol⁻¹; hydrogen contributes 10 × 1.008 g mol⁻¹ = 10.080 g mol⁻¹. The molar mass of p-xylene is therefore 96.088 g mol⁻¹ + 10.080 g mol⁻¹ = 106.168 g mol⁻¹. Unit cancellation in the quotient 24.832 g ÷ 106.168 g mol⁻¹ yields 0.23389345 mol. When rounded to the five significant figures carried by the sample mass, the p-xylene amount present is 0.23389 mol.