Some of the substances commonly used in stomach antacids are $\mathrm{MgO}, \mathrm{Mg}(\mathrm{OH})_{2},\( and \)\mathrm{Al}(\mathrm{OH})_{3.}$ a. Write a balanced equation for the neutralization of hydrochloric acid by each of these substances. b. Which of these substances will neutralize the greatest amount of 0.10 M HCl per gram?

Let's write balanced equations for the neutralization of hydrochloric acid by MgO, Mg(OH)₂, and Al(OH)₃. a. For MgO: \(MgO + 2HCl \to MgCl_{2} + H_{2}O\) b. For Mg(OH)₂: \(Mg(OH)_{2} + 2HCl \to MgCl_{2} + 2H_{2}O\) c. For Al(OH)₃: \(Al(OH)_{3} + 3HCl \to AlCl_{3} + 3H_{2}O\)

To find which of these substances can neutralize the greatest amount of 0.10 M HCl per gram, we'll first need to calculate the number of moles of HCl neutralized per gram of each substance. a. For MgO: Molar mass of MgO: Mg (24.31 g/mol) + O (16.00 g/mol) = 40.31 g/mol Moles of HCl neutralized per gram of MgO: (1 mole MgO / 40.31 g) * 2 moles HCl / 1 mole MgO = 0.0496 moles HCl/g b. For Mg(OH)₂: Molar Mass of Mg(OH)₂: Mg (24.31 g/mol) + 2 * O (16.00 g/mol) + 2 * H (1.01 g/mol) = 58.33 g/mol Moles of HCl neutralized per gram of Mg(OH)₂: (1 mole Mg(OH)₂ / 58.33 g) * 2 moles HCl / 1 mole Mg(OH)₂ = 0.0343 moles HCl/g c. For Al(OH)₃: Molar Mass of Al(OH)₃: Al (26.98 g/mol) + 3 * O (16.00 g/mol) + 3 * H (1.01 g/mol) = 78.01 g/mol Moles of HCl neutralized per gram of Al(OH)₃: (1 mole Al(OH)₃ / 78.01 g) * 3 moles HCl / 1 mole Al(OH)₃ = 0.0385 moles HCl/g

Now that we have the moles of HCl neutralized per gram for each substance, we can compare them: MgO: 0.0496 moles HCl/g Mg(OH)₂: 0.0343 moles HCl/g Al(OH)₃: 0.0385 moles HCl/g The substance that neutralizes the greatest amount of HCl per gram is MgO, with 0.0496 moles HCl/g.