Barium chloride solution, acidified with hydrochloric acid, is used to test for sulfate ions because the acid prevents the precipitation of barium carbonate.

Magnesium reacts rapidly with steam to produce magnesium hydroxide and hydrogen gas.

In the industrial extraction of titanium from titanium(IV) chloride, magnesium acts as a reducing agent.

A slurry of calcium oxide is used in flue-gas desulfurization to react with acidic sulfur dioxide to produce calcium sulfite.