Question

Pkb of CN- is 4.7 the ph of 0.5 M aqueos NACN SOLUTION IS

Answer 1

CN- + H2O <> HCN + OH-

Initial concentration

0.5 . . . . . . .. . .. .0 .. . . . 0

at equilibrium

0.5-x .. . . . . . . . . x . .. . .x

Kb = 10^-4.7 = 1.99x 10 ^-5 = x^2 / 0.5 - x

x = [OH-] = 0.00315 M

pOH = 2.59

pH = 14 - 2.5 = 11.5

The answer is 2)

Answer 2

hope this helps you !!!

pls mark as brainliest  by pressing the crown icon below   ^_^