The poison strychnine is a weakly basic compound with Kb = 1.8 „e 10ƒ{6. What is the pH of a 0.058 M solution of strychnine?

a. 3.49
b. 7.30
c. 8.26
d. 10.51
e. 12.76

1 answer

If we call strychnine, B, then
B + HOH ==> BH^+ + OH^-

Kb = (BH^+)(OH^-)/(B)
Set up an ICE chart, substitute, and solve for OH^-, convert to pOH, then to pH.