Answer:
- [H₃O⁺] = 7.586×10⁻⁴ M
Explanation:
The <em>pH</em> of a solution is a measure of the <em>molar concentration of </em><em>H₃O⁺</em> ions in the solution.
The mathematical expresssion that states the relation between the molar concentration of H₃O⁺ ions and the pH of the solution is:
- pH = - log [H₃O⁺].
This is pH is numerically equal to the negative decimal logarithm of the molar concentration of H₃O⁺.
The square brackets are used to indicate molar concentration.
Thus:
- pH = - log [H₃O⁺] ← equation
- 3.120 = -log [H₃O⁺] ← substituting values
- - 3.120 = log [H₃O⁺] ← product property of the multiplication
← antilogarithm property
- [H₃O⁺] = 7.586×10⁻⁴ M ← result