Magnesium oxide (MgO) reacts with nitric acid (HNO₃) to produce magnesium nitrate (Mg(NO₃)₂).

This is a classic acid-base neutralization where the base MgO combines with the acid to form the salt and water.

Chemical Equation

The balanced reaction follows a straightforward stoichiometry:

  • MgO + 2HNO₃ → Mg(NO₃)₂ + H₂O

Magnesium, with its +2 charge, pairs perfectly with two nitrate ions (NO₃⁻) from the acid. No other common acid yields nitrate as the anion in the salt.

Why Nitric Acid?

  • Acids like sulfuric (H₂SO₄) produce magnesium sulfate, hydrochloric (HCl) yields chloride—only nitric acid delivers the nitrate salt.
  • Sources confirm this preparation method universally, from lab manuals to chemistry sites.

Reaction Insights

Nitric acid dissolves MgO efficiently due to its strength and nitrate solubility.

  • Practical note : Often used in fertilizers; the reaction is exothermic, releasing heat.
  • Multiple viewpoints align—no exceptions noted in educational resources.

TL;DR: The acid is nitric acid (HNO₃).

Information gathered from public forums or data available on the internet and portrayed here.