17. Acid and Base Equilibrium

If the Kb of NH₃ is 1.76 x 10^-5, determine the acid dissociation constant of its conjugate acid. 

Which Bronsted-Lowry base has the greatest concentration of hydroxide ions? 

Which Bronsted-Lowry acid has the weakest conjugate base?

Hypobromous acid (K_a = 2.8 × 10⁻⁹) and hydrocyanic acid (K_a = 4.9 × 10⁻¹⁰) are both weak acids. Determine if reactants or products are favored in the following reaction.

HBrO (aq) + CN⁻ (aq) ⇌ BrO⁻ (aq) + HCN (aq)

a) reactants        b) products            c) both directions are favored equally   d) neither direction is favored

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 

Determine the pK_a given the Kb of the following bases:

i) NH₃               K_b = 1.76 × 10⁻⁵ ; NH₄⁺           pK_a = ____________

ii) C₆H₅NH₂     K_b = 3.9 × 10⁻¹⁰ ; C₆H₅NH₃⁺  pK_a = ____________