Study of the First Element — Hydrogen — Question 25

These metals arranged in order of their activity with water:

Na > Ca > Mg > Fe

Equations for reaction of metals with water:

Sodium

$2\text{Na} + \underset{\text{cold water}}{2\text{H}_2\text{O}} \longrightarrow 2\text{NaOH} + \text{H}_2$

Calcium

$\text{Ca} + \underset{\text{cold water}}{2\text{H}_2\text{O}} \longrightarrow \text{Ca(OH)}_2 + \text{H}_2$

Magnesium

$\text{Mg} + \underset{\text{boiling water}}{\text{H}_2\text{O}} \longrightarrow \text{MgO} + \text{H}_2$

Iron

$3\text{Fe} + \underset{\text{[steam]}}{4\text{H}_2\text{O}} \rightleftharpoons \underset{\text{[magnetic oxide of iron]}}{\text{Fe}_3\text{O}_4} + 4\text{H}_2$