Calculate the pH of a 0.021 M NaCN solution.[K_a(HCN)= 4.9 × 10^-10] A)1.68 B)3.18 C)5.49 D)7.00 E)10.82

Question

Quizplus · Accepted Answer

NaCN is a salt of a weak acid (HCN) and a strong base (NaOH). In solution, CN⁻ will hydrolyze to form OH⁻, making the solution basic. The Kb for CN⁻ can be calculated using Kw/Ka = Kb. Then, using the concentration of CN⁻ and Kb, the concentration of OH⁻ can be found, and subsequently, the pOH and pH. The pH is approximately 10.82.

Calculate the PH of a 0