Methanoic acid is a weak acid and hydrochloric acid is a strong acid.

Describe the reaction with magnesium to show that methanoic acid is an acid.

HCOOH + Mg -> Mg(COO)₂ + H₂

Observations Mg ribbon gets hydrogen bubbles cause

Compare this with a similar reaction of hydrochloric acid to demonstrate why methanoic is a weak acid and the hydrochloric acid is a strong acid.

HCl + Mg -> MgCl₂ + H₂

The rate of reaction for the HCl is than the rate of reaction for methanoic acid so there are bubbles produced per second.

This is because all of the HCl breaks down to produce a higher concentration of ions in the solution.

Weak acids set up an equilibrium and when ions react the equilibrium shifts to replenish the ions in solution.

For a given concentration and volume of acid

The total volume of gas produced will be the same for both acids.