Understanding the Relationship

* pH is a measure of the acidity or alkalinity of a solution. It's based on the concentration of hydronium ions (H₃O⁺).

* The formula relating pH to hydronium ion concentration is:

pH = -log[H₃O⁺]

Solving for Hydronium Ion Concentration

1. Rearrange the formula:

[H₃O⁺] = 10⁻pH

2. Plug in the given pH value:

[H₃O⁺] = 10⁻(-0.120)

3. Calculate:

[H₃O⁺] = 10⁰.₁₂⁰

[H₃O⁺] ≈ 1.32 M

Therefore, the hydronium ion concentration of a solution with a pH of -0.120 is approximately 1.32 M.

Important Note: A pH of -0.120 is extremely acidic. This is a very high concentration of hydronium ions, far beyond what is typically found in everyday solutions.