Name two metals that can displace hydrogen from dilute acids to form metal salts and hydrogen gas.

• Metals that are placed above hydrogen in the reactivity series like potassium, sodium, zinc, etc. can displace hydrogen from dilute acids to form metal salts and hydrogen gas.
• The reactivity series is the list of metals in the decreasing order of their reactivity.
• The most reactive metal occupies the topmost position.
• The least reactive metal is at the bottom.
• When Sodium reacts with dilute hydrochloric acid it forms sodium chloride and hydrogen gas.
• $\underset{\mathrm{Sodium}}{2\mathrm{Na}\left(\mathrm{s}\right)}+\underset{\mathrm{Hydrochloric}\mathrm{acid}}{2\mathrm{HCl}\left(\mathrm{dil}\right)}\to \underset{\mathrm{Sodium}\mathrm{chloride}}{2\mathrm{NaCl}\left(\mathrm{aq}\right)}+\underset{\mathrm{Hydrogen}\mathrm{gas}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}$
• When Potassium reacts with dilute sulphuric acid it forms potassium sulfate and hydrogen gas.
• $\underset{\mathrm{Potassium}}{2\mathrm{K}\left(\mathrm{s}\right)}+\underset{\mathrm{Sulphuric}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{dil}\right)}\to \underset{\mathrm{Potassium}\mathrm{sulphate}}{{\mathrm{K}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)}+\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}$

Hence, Sodium and Potassium are two metals that can displace hydrogen from dilute acids to form metal salts and hydrogen gas.