Question

In water, HCl dissolves into the ions H+ and Cl-. When HCl is added to pure

water, the pH will__________

Answer 1

When HCl is added to pure water, the pH will decrease because HCl is a strong acid that fully dissociates into hydrogen ions (H+) and hydronium ions (H3O+), making the solution more acidic.

Step-by-step explanation:

When HCl is added to pure water, the pH will decrease. This occurs because HCl is a strong acid that dissociates completely in water, providing free hydrogen ions (H+), which increase the solution's acidity. The reaction is as follows:

HCl Dssociation:

HCl(g) → H+(aq) + Cl️(aq)

Addition of water creates the hydronium ion (H3O+):

HCl(aq) + H2O(l) → H3O*(aq) + Cl️(aq)

These hydronium ions are responsible for the lower pH. Since the concentration of H3O* ions is equal to the concentration of initially added HCl, the pH of the solution can be calculated. The Cl️ ion, on the other hand, does not affect the pH because it is a neutral product in the reaction.