How do metals in the reactivity series react with water?

Metals in the reactivity series react with water to produce a metal hydroxide and hydrogen gas.

In the reactivity series, metals are listed in order of their reactivity, from most reactive to least reactive. This reactivity determines how a metal will react with water. The most reactive metals, such as potassium, sodium, and calcium, react with water at room temperature. When they come into contact with water, they react vigorously, producing a metal hydroxide and hydrogen gas. For example, when sodium (Na) reacts with water (H2O), it forms sodium hydroxide (NaOH) and hydrogen gas (H2).

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

This reaction is highly exothermic, meaning it releases a lot of heat. This heat is enough to ignite the hydrogen gas that is produced, causing a flame.

Metals that are less reactive, such as magnesium, aluminium, zinc, and iron, do not react with water at room temperature. However, they will react with steam to produce a metal oxide and hydrogen gas. For instance, when magnesium (Mg) reacts with steam (H2O), it forms magnesium oxide (MgO) and hydrogen gas (H2).

Mg(s) + H2O(g) → MgO(s) + H2(g)

The least reactive metals, such as copper, silver, and gold, do not react with water at all. These metals are found at the bottom of the reactivity series.

Understanding how metals react with water is important in many areas of chemistry, including predicting the outcomes of chemical reactions and understanding the properties of different metals. It's also crucial in various industrial processes, such as the production of metals and their compounds.