Question

Complete the statement detailing the relative change in [H+] when the pH of a solution changes from 6.40 to 8.40. At pH 8.40, the [H+] would be ____ that at pH 6.40.

Answer 1

The relative change in [H+] when the pH changes from 6.40 to 8.40 is calculated using the formula [H+]final = [H+]initial * 10^(pHfinal - pHinitial). The [H+] at pH 8.40 would be 1.00 times that at pH 6.40.

Step-by-step explanation:

The pH scale is logarithmic, which means that a pH difference of 1 corresponds to a difference of a factor of 10 in hydronium ion concentrations. To determine the relative change in [H+] when the pH changes from 6.40 to 8.40, we calculate:

[H+]final = [H+]initial * 10(pHfinal - pHinitial)

[H+]final = (1.0 x 10-6) * 10(8.40 - 6.40)

[H+]final = 0.01 * 102

[H+]final = 0.01 * 100 = 1.00

Therefore, at pH 8.40, the [H+] would be 1.00 times that at pH 6.40.