Which formula can be used to calculate the pH of a weak acid given its pKa and concentration?

What is the H₃O⁺ concentration of a 0.250 M hydrofluoric acid (HF) solution, given that the acid dissociation constant (Ka) for HF is 6.8 x 10⁻⁴?

What is the pH of a 0.010 M HNO₂ solution, given that the acid dissociation constant (Ka) for HNO₂ is 4.0 x 10⁻⁴?

What is the pH of a solution that is 8.0 × 10⁻² M in H₂CO₃, given that the first dissociation constant (Ka1) of H₂CO₃ is 4.3 × 10⁻⁷?

Find the pH of a solution that is 9.0×10⁻² M in H₂CO₃. Express your answer using two decimal places.

If 17.0 mL of glacial acetic acid (pure HC2H3O2; Ka=1.8×10⁻⁵) is diluted to 1.65 L with water, what is the pH of the resulting solution? The density of glacial acetic acid is 1.05 g/mL.

If a solution of HF (Ka = 6.8 × 10⁻⁴) has a pH of 2.50, what is the initial concentration of hydrofluoric acid in the solution?

The pH of a solution containing HIO3 (Ka = 1.7 × 10⁻¹) and KIO3 is 1.00. If the molarity of HIO3 is 0.025 M, what is the molarity of KIO3?

The venom of stinging ants contains formic acid, HCOOH, with a dissociation constant (Ka) of 1.8 × 10⁻⁴ at 25 °C. What is the pH of a 0.055 M solution of formic acid?