To write the balanced equations for these reactions, we need to ensure that the number of atoms of each element is the same on both sides of the equation.
a) Reaction of Magnesium Metal with Hydrochloric Acid
The reaction between magnesium (Mg) metal and hydrochloric acid (HCl) can be represented as:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
In this reaction, one magnesium atom reacts with two molecules of hydrochloric acid to produce one molecule of magnesium chloride and one molecule of hydrogen gas. We have balanced the equation by ensuring that there are two chlorine atoms and two hydrogen atoms on each side.
b) Reaction of Magnesium Oxide with Hydrochloric Acid
The reaction of magnesium oxide (MgO) with hydrochloric acid can be written as:
MgO(s) + 2HCl(aq) → MgCl2(aq) + H2O(l)
Here, one molecule of magnesium oxide reacts with two molecules of hydrochloric acid to form one molecule of magnesium chloride and one molecule of water. Again, we have maintained the balance of atoms on both sides of the equation.
Both equations demonstrate simple chemical reactions where a metal and an oxide react with an acid to form a salt and a gas or water.