Chemical Reactions of Metals

The reaction of metals in hydrochloric acid. From left to right are samples of magnesium, zinc, iron and lead in test tubes with a solution of hydrochloric acid. Each metal reacts differently to the acid. Magnesium (Mg) ribbon reacts vigorously and produces hydrogen (H2) gas (bubbles) and a solution of magnesium chloride (MgCl2). Zinc (Zn) reacts less vigorously with hydrochloric acid, producing zinc chloride (ZnCl2) and hydrogen (H2) gas (bubbles). The iron (Fe) in a steel screw is mainly reacting at the cut surface. This reaction leads to the formation of iron II chloride (FeCl2) and hydrogen (H2), which bubbles off as a gas. The sample of lead (Pb) does not react with the acid. Because it is unreactive, lead is also highly resistant to corrosion and is used to contain corrosive liquids such as sulphuric acid.