Property 2: The reaction of metals with water
In general, metals react with water to form metal oxides and hydrogen gas.
Metal + Water → Metal Oxide + Hydrogen
And if the ‘metal oxide’ formed is soluble in water, it will dissolve to further form ‘metal hydroxide’.
Metal Oxide + Water → Metal Hydroxide
For example,
- Metals like sodium or potassium react violently with cold water. The released Hydrogen immediately catches fire due to the violent nature.
Sodium + Water → Sodium Hydroxide + 𝑯𝟐
Potassium + Water → Potassium Hydroxide + 𝑯𝟐
Thus sodium and potassium are very reactive.
- Calcium reacts with cold water.
Calcium + Water → Calcium Hydroxide +𝑯𝟐
The heat is not enough for the hydrogen to catch fire. Here calcium starts floating because bubbles of hydrogen gas formed stick to the surface of the metal.
- Magnesium reacts with hot water to form magnesium hydroxide and hydrogen gas.
Magnesium + Hot Water → Magnesium Hydroxide + 𝑯𝟐
It starts floating due to the bubbles of hydrogen gas sticking to its surface.
- Aluminium, iron, and zinc react with steam (water in the gaseous state), to form a metal oxide and hydrogen.
Aluminium + Steam → Aluminium oxide +𝑯𝟐
Iron + Steam → Iron oxide + 𝑯𝟐
Zinc + Steam → Zinc oxide + 𝑯𝟐
- Metals like lead, copper, silver, and gold don’t react with water at all.
Order of reactivity
Summary
| The Reaction of Metals with Water | In general, metals react with water to form metal oxides and hydrogen gas.
Metal + Water → Metal Oxide + Hydrogen
If the ‘metal oxide’ formed is soluble in water, it will dissolve to further form ‘metal hydroxide’. Metal Oxide + Water → Metal Hydroxide |