Question

Gastric juice contains hydrochloric acid, HCl. Milk of Magnesia, a suspension of solid Mg(OH)₂ in an aqueous medium, is sometimes used to neutralize excess stomach acid. Write a complete balanced equation for the neutralization reaction, and identify the conjugate acid-base pairs.

a) Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O; Mg(OH)₂/H₂O, HCl/Cl⁻
b) Mg(OH)₂ + HCl → MgCl₂ + H₂O; Mg(OH)₂/H₂O, HCl/Cl⁻
c) Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O; Mg(OH)₂/OH⁻, HCl/Cl⁻
d) Mg(OH)₂ + HCl → MgCl₂ + H₂O; Mg(OH)₂/OH⁻, HCl/Cl⁻

Answer 1

The balanced chemical equation for the neutralization of HCl by Mg(OH)2 is Mg(OH)2 + 2HCl → MgCl2 + 2H2O (c), forming magnesium chloride and water, with conjugate pairs Mg(OH)2/OH- and HCl/Cl-.

Step-by-step explanation:

The correct balanced chemical equation for the neutralization reaction between hydrochloric acid (HCl) and magnesium hydroxide (Mg(OH)2) is Mg(OH)2 + 2HCl → MgCl2 + 2H2O. In this equation, the milk of magnesia (Mg(OH)2) reacts with the gastric juice (HCl) to form magnesium chloride (MgCl2) and water (H2O). The conjugate acid-base pairs in this reaction are Mg(OH)2/OH− and HCl/Cl−.

The complete balanced equation for the neutralization reaction between HCl and Mg(OH)₂ is:

Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O

In this reaction, the conjugate acid-base pairs are:

Mg(OH)₂ / OH⁻ and HCl / Cl⁻