What is the pH of a 0.250 M NH₄Cl solution? K_b for NH₃ = 1.8 × 10⁻⁵.

Which Bronsted-Lowry acid has the weakest conjugate base?

Identify a Bronsted-Lowry acid with weakest conjugate base.

a) H₃BO₃  K_a = 5.4 × 10⁻¹⁰

b) HF K_a = 3.5 × 10⁻⁴

c) HNO₂  K_a = 4.6 × 10⁻⁴

d) HClO K_a = 2.9 × 10⁻⁸

Identify which of the compounds is the strongest species.

a) Iodic acid pK_a = 0.80  b) Acetic acid pK_b = 9.24 c) Formic acid pK_a = 3.75 d) Ammonium pK_b = 4.75