Final answer:
The neutral pH at a temperature where the autoionization constant of water (Kw) is 2.42 × 10^-14, such as 37 °C, can be determined by calculating half of the pKw, which results in a pH of approximately 6.81.
Step-by-step explanation:
The neutral pH at a given temperature can be determined by understanding the autoionization constant of water (Kw) at that temperature. For instance, at 25 °C, the Kw is 1 × 10-14, and the pH of a neutral solution is 7. However, Kw changes with temperature, affecting the neutral pH value.
At 37 °C, the Kw is 2.42 × 10-14. To find the neutral pH for this temperature, we can use the formula:
pH + pOH = pKw
Since the solution is neutral, [H3O+] is equal to [OH-], meaning pH is equal to pOH. Therefore, the pH of a neutral solution at 37 °C would be half of pKw.
Calculating pKw, which is the negative logarithm of Kw, we get:
pKw = −log(2.42 × 10-14) ≈ 13.62
Hence, for a neutral solution, pH would be approximately half of pKw:
pH = pOH ≈ 13.62 / 2 ≈ 6.81