Final answer:
To calculate the pH of a 2.30 x 10⁻⁷ M NaOH solution, you determine the concentration of OH⁻ ions, use it to find the concentration of H₃O⁺, and then take the negative log of that concentration. The pH is found to be 7.36.
Step-by-step explanation:
To calculate the pH of a 2.30 x 10⁻⁷ M NaOH solution, we must first recognise that NaOH is a strong base and will completely dissociate in water, producing an equivalent concentration of OH⁻ ions. Since the given concentration of NaOH is 2.30 x 10⁻⁷ M, this is also the concentration of OH⁻ ions in the solution. The pH of the solution can be found by first calculating the concentration of H3O⁺ (the hydronium ion) using the formula [H3O⁺] = 10⁻¹⁴ / [OH⁻].
Plugging in the numbers we get: [H3O⁺] = 10⁻¹⁴ / 2.30 x 10⁻⁷ = 4.35 x 10⁻⁸ M. To find the pH, we take the negative logarithm of the hydronium ion concentration: pH = −log [H3O⁺] = −log(4.35 x 10⁻⁸) = 7.36. Hence, the pH of the 2.30 x 10⁻⁷ M NaOH solution is 7.36.