When an acid solution is diluted, the concentration of hydronium ions (H₃O⁺) decreases. This is because adding water increases the total volume of the solution, while the amount of acid (and thus H₃O⁺ ions) remains the same. Dilution essentially spreads the same number of hydronium ions over a larger volume, lowering their concentration.
Here’s a more detailed explanation:
Dilution Definition:
Dilution refers to the process of reducing the concentration of a solution by adding more solvent (in this case, water).
Concentration Calculation:
Concentration is defined as the amount of solute (the acid in this case) per unit volume of solution.
Effect of Dilution on H₃O⁺:
When diluting an acid, the total volume of the solution increases, but the number of H₃O⁺ ions (formed from the acid) remains the same. This means that the same number of H₃O⁺ ions are now distributed across a larger volume.
Result:
This spreading of the H₃O⁺ ions over a larger volume results in a lower concentration of hydronium ions per unit volume.