How Does The PH Of The Solution Change During The Reaction Between Sodium Metabisulfite And Water?

The reaction between sodium metabisulfite and water can be represented as follows: Na2S2O5 + H2O → 2NaHSO3.

This is an acid-base reaction that produces two moles of sodium bisulfite (NaHSO3) for every mole of sodium metabisulfite (Na2S2O5) that reacts with water.

Since the formation of NaHSO3 involves the release of hydrogen ions (H+), this reaction leads to an increase in the concentration of H+ ions in the solution, resulting in a decrease in pH.

Therefore, the pH of the solution decreases during the reaction between sodium metabisulfite and water. The extent of the pH change will depend on the initial concentration of Na2S2O5 and the volume of water used in the reaction.