Calculate the pH at the equivalence point for the titration of a solution containing 1250.0 mg of hilariamine (MW = 92.5 g/mol, Kb = 8.1×10−4) with 0.1000 M HCl solution. The volume of the solution at the equivalence point is 175.0 mL.

(I got the answer to be 12.0208 but it seems wrong because pH isn't suppose to be that high)

See your post above.

12.1

Humongous wot? All jokes aside, I want you to be my yolkmate

To calculate the pH at the equivalence point of a titration, we can use the concept of acid-base neutralization. At the equivalence point, the number of moles of acid (HCl) added is equal to the number of moles of base (hilariamine) present in the solution.

First, let's calculate the number of moles of hilariamine in the solution:
Number of moles = mass / molar mass
Given that the mass of hilariamine is 1250.0 mg and the molar mass is 92.5 g/mol,
Number of moles = 1250.0 mg / (92.5 g/mol) = 0.0135 mol

Since hilariamine is a base, we can use the equation for the hydrolysis of the base to find the concentration of OH- ions at the equivalence point:
Kb = [OH-][H3A] / [H3O+]
Given that the Kb value for hilariamine is 8.1×10−4, and at the equivalence point, [H3A] = 0 (as it is fully neutralized), we can rearrange the equation to find the concentration of OH- ions:

[OH-] = √(Kb * [H3A])

[OH-] = √(8.1×10−4 * 0.0135 mol / 0.175 L) (converting 175.0 mL to L)

[OH-] = √(8.1×10−4 * 0.0135 mol / 0.175 L) = 0.00885 M

Since the concentration of OH- ions is known, we can calculate the concentration of H3O+ ions (which is equal to the concentration of H+ ions) using the equation for water:

[H3O+] * [OH-] = Kw

where Kw is the ion product constant for water (1.0 x 10^-14 at 25°C). At the equivalence point, [OH-] = 0.00885 M, so

[H3O+] * 0.00885 M = 1.0 x 10^-14

[H3O+] = (1.0 x 10^-14) / 0.00885 M = 1.13 x 10^-12 M

Now, we can calculate the pH using the formula for pH:

pH = -log[H3O+]

pH = -log(1.13 x 10^-12) = 11.94

Therefore, the pH at the equivalence point for this titration is approximately 11.94, not 12.0208 as previously calculated. This pH value is consistent with the titration of a weak base with a strong acid.