Hydrochloric acid (HCl) is indeed a strong acid, which means it completely dissociates in water. When HCl dissolves in water, it releases hydrogen ions (H⁺) and chloride ions (Cl⁻). The concentration of hydrogen ions in the solution determines its pH level.
For a strong acid like HCl, the pH can be calculated using the formula:
pH = -log[H⁺]
If you have a 1 Molar (1 M) solution of HCl, the concentration of hydrogen ions [H⁺] will also be 1 M. Plugging this into the formula:
pH = -log(1) = 0
Therefore, a 1 M solution of hydrochloric acid would have a pH of 0. However, the pH can vary depending on the concentration of the HCl solution. For example, a 0.1 M solution of HCl would have a pH of 1, and a 0.01 M solution would have a pH of 2.
In summary, the pH of hydrochloric acid depends on its concentration, but for a strong acid like HCl, the pH is generally very low, often close to 0 for highly concentrated solutions.