17. Acid and Base Equilibrium

Determine the pH of a solution made by dissolving 6.1 g of sodium cyanide, NaCN, in enough water to make a 500.0 mL of solution. (MW of NaCN = 49.01 g/mol). The K_a value of HCN is 4.9 × 10⁻¹⁰.

An unknown weak base has an initial concentration of 0.750 M with a pH of 8.03. Calculate its equilibrium base constant. 

What is the pH of a 0.320 M solution of Ca(NO₂)₂ (ka of HNO₂ is 4.5 × 10^-4)?

What is the pH of a 0.750 M solution of NaCN (K_a of HCN is 4.9 × 10^-10)?

How can the pH of a solution be calculated if the pOH is known?

The K_b of methylamine is 4.4 x 10^–4. What is the approximate [OH^–] of a 1 M solution of methylamine?