What is the pH of a solution with [H₃O+] = 3.0 × 10^-3 M?

Question

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The given concentration is of a cation, [H₃O+], which is an acid. To find the pH, we need to find the concentration of H+ ions in the solution. The acid dissociation reaction is: H₃O+ ⇌ H+ + ₃O The equilibrium constant expression is: Ka = [H+][₃O-] / [H₃O+] We are given the concentration of [H₃O+] as 3.0 × 10^-3 M, but we do not know the concentrations of [H+] or [₃O-]. However, we can assume that the concentration of [₃O-] is negligible compared to the initial concentration of [H₃O+]. Therefore, we can simplify the equilibrium expression as: Ka = [H+][₃O-] / [H₃O+] ≈ [H+][₃O-] / [H₃O+] Since the equilibrium constant for this acid, Ka, is known to be 1.1 x 10^-8, we can use this value to find the concentration of [H+]. Ka = [H+][₃O-] / [H₃O+] 1.1 x 10^-8 = [H+]^2 / [H₃O+] [H+]^2 = 1.1 x 10^-8 x 3.0 x 10^-3 [H+]^2 = 3.3 x 10^-11 [H+] = 1.8 x 10^-6 M Using the definition of pH, we can find the pH of the solution: pH = -log[H+] pH = -log(1.8 x 10^-6) pH = 2.52 Therefore, the answer is B, 2.52.

What Is the PH of a Solution with [H3O+] =

What Is the PH of a Solution with [H₃O+] =