Consider the diprotic acid, oxalic acid. Identify the chemical equations and the equilibrium expressions for each ionization step.

Choose the correct statement

A 0.135 M solution of diprotic acid H₂A has a pH of 5.85. A 0.135 M solution of the salt KHA is basic. Which of the following is a reasonable value for the pK_a2 of this acid?

We are given a diprotic acid H₂A. It has a K_a1 = 4.2x10^-6 and K_a2 = 6.8x10^-9

Calculate the pH of 0.0700 M solution of H₂A. Calculate the concentrations of H₂A and A^2- for this solution at equilibrium

The mixture of 0.14 M HCl and 0.19 M HF has a pH of _.

0.200 M KOH is used to titrate 50.0 mL samples of 0.200 M HNO₃ and 0.200 M HNO₂, individually. Match them to their corresponding titration curve.

Determine the pH and identify the main source of H₃O⁺ in a 1.2 × 10^-9 M solution of HCl. Also, determine the pH of 1.2 × 10^-7 M HCl. (Hint: pH should not exceed 7.)

Citric acid (HOC(CO₂H)(CH₂CO₂H)₂) is a weak triprotic acid. Write balanced dissociation equations and corresponding equilibrium expressions for each dissociation step.

Calculate the pH and the molarities of all species (H₃AsO₄, H₂AsO₃^–, HAsO₄^2–, AsO₄^3–, H₃O⁺, and OH^–) in a 9.50 % (by mass) solution of arsenic acid with a density of 1.1033 g/mL. The equilibrium constants are:

K_a1 = 6.46×10^–3

K_a2 = 1.14×10^–7

K_a3 = 3.16×10^–12

What is the pH and [H⁺] of a 0.24 M H₃A (K_a1 = 6.3x10^-3, K_a2 = 5.9x10^-8, K_a3 = 2.2x10^-12) polyprotic acid solution?

Identify whether the compounds are strong acids, weak acids, strong bases, weak bases or, others in an aqueous solution. 

CsOH, H₂SO₄, CH₃NH₂, HI, CHCOOH, KF, NH₃, HCN, H₃PO₄, Mg(OH)₂