A solution has a pH of 8.72.What is the value of [H⁺]? A) 5.2 * 10^-⁶ B) 1.9 *10^-⁹ C) 5.2* 10^-⁸ D) 1.9 * 10^-⁵

Question

Quizplus · Accepted Answer

The pH of the solution tells us that it is basic, which means it contains a higher concentration of hydroxide ions (OH-) than hydrogen ions (H+). This indicates that the solution is a weak acid.
From the given answer choices, we need to look for the one that has a value of [HS1U1P1+S1S1P0] that is characteristic of a weak acid. A weak acid has a low concentration of hydronium ions (H3O+), which means that the concentration of HS1U1P1 is higher relative to S1S1P0. This eliminates choices A and C.
Next, we can use the pH to calculate the concentration of H3O+ using the formula pH = -log[H3O+]. Plugging in the given pH value of 8.72, we get [H3O+] = 1.9 x 10^(-9) mol/L.
Since the solution is a weak acid, we can assume that it is a monoprotic acid (meaning it can donate only one proton to water). This tells us that the concentration of HS1U1P1 is equal to the concentration of H3O+.
Now we can use the given answer choices to find the concentration of HS1U1P1+S1S1P0. We can plug in the calculated value of [H3O+] and solve for the sum of the concentrations of HS1U1P1 and S1S1P0.
Only choice B gives us a sum of 1.9 x 10^(-10) mol/L, which matches our calculated value. Therefore, the correct answer is B.

A Solution Has a PH of 8