Chapter 5, Problem 89IAE

The active ingredients h a particular antacid tablets are aluminum hydroxide, $\text{Al}{\left(\text{OH}\right)}_{\text{2}}\text{,}$ and magnesium hydroxide, $\text{Mg}{\left(\text{OH}\right)}_{\text{2}}$ . A 5.00 × 10² sample of the active ingredients was dissolved in mL of 0.500 M HCI. The resulting solution, which was still acidic, required 16.5 mL of 0.377 M NaOH for neutralization. What are the mass percentages of $\text{Al}{\left(\text{OH}\right)}_{\text{2}}\text{,}$ and $\text{Mg}{\left(\text{OH}\right)}_{\text{2}}$ in the sample?