Question

Which is the correct equation for the reaction of magnesium with hydrochloric acid to produce hydrogen and magnesium chloride?

a.mg + 2 hcl → h2 + mgcl2
b.mg + hcl → h + mgcl
c.2 mg + 6 hcl → 3 h2 + 2 mgcl2
d.mg + 2 hcl → 2 h + mgcl2
e.mg + 3 hcl → 3 h + mgcl2?

Answer 1

Answer is: a. Mg + 2HCl → H₂ + MgCl₂.
Reduction hald reaction: 2H⁺ + 2e⁻→ H₂.
Oxidation half reaction: Mg⁰ → Mg²⁺ + 2e⁻.
In this chemical reaction, magnesium lost two electrons (oxidation, change oxidation number from 0 to +2) and hydrogen gain that two electrons (reduction, change oxidation number from +1 to 0).