A mass of 0.4113 g of an unknown acid,HA,is titrated with sodium hydroxide,NaOH.If the acid reacts with 28.10 mL of 0.1055 M aqueous sodium hydroxide,what is the molar mass of the acid?

Question

Quizplus · Accepted Answer

First, calculate the moles of NaOH used: $28.10 \, \text{mL} \times \frac{0.1055 \, \text{mol}}{1000 \, \text{mL}} = 0.002965 \, \text{mol}$. Since the reaction between HA and NaOH is 1:1, the moles of HA are also 0.002965. The molar mass of HA is then calculated by dividing the mass of the acid by the moles of acid: $\frac{0.4113 \, \text{g}}{0.002965 \, \text{mol}} = 138.7 \, \text{g/mol}$.

A Mass of 0