Chemistry » Acid-Base and Redox Reactions » Acid-Base Reactions

Acid and Metal Oxide

Acid and metal oxide

When an acid reacts with a metal oxide a salt and water are also formed. Some examples are:

• $$2\text{HCl (aq)} + \text{Na}_{2}\text{O (aq)} \rightarrow \text{H}_{2}\text{O (l)} + 2\text{NaCl}$$
• $$2\text{HBr (aq)} + \text{MgO} \rightarrow \text{H}_{2}\text{O (l)} + \text{MgBr}_{2}\text{(aq)}$$
• $$6\text{HCl (aq)} + \text{Al}_{2}\text{O}_{3} \text{(aq)} \rightarrow 3\text{H}_{2}\text{O (l)} + 2\text{AlCl}_{3}\text{(aq)}$$

We can write a general equation for the reaction of a metal oxide with an acid: $2y\text{H}^{+}\text{(aq)} + \text{M}_{x}\text{O}_{y}\text{(aq)} \rightarrow y\text{H}_{2}\text{O (l)} + x\text{M}^{n+}\text{(aq)}$ Where $$n$$ is the group number of the metal. The $$x$$ and $$y$$ represent the ratio in which the metal combines with the oxide and depends on the valency of the metal.