Question

Name the metal which can displace hydrogen from water.

Answer 1

Reactivity series: Reactivity series is the arrangement of metals in the decreasing order of their reactivity in a tabular form.

• In the reactivity series, a metal can displace the metals present below that element in the reactivity series.
• So, the metal present at the top in the reactivity series can displace hydrogen from water and dilute acids.

Identifying the metal which can displace hydrogen from water:

• Sodium is a metal that is present above hydrogen in reactivity series and reacts vigorously with cold water and displaces hydrogen.
• The balanced chemical equation can be represented as:

$\underset{\mathrm{Sodium}}{\mathrm{Na}\left(\mathrm{s}\right)}+\underset{\mathrm{Cold}\mathrm{water}}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\to \underset{\mathrm{Sodium}\mathrm{hydroxide}}{\mathrm{NaOH}\left(\mathrm{aq}\right)}+\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}$