0.194M NaOH and 0.268 M NH4CL Find concentration of OH

Answer 1

I would try this. Set up a RICE chart
R......OH^- + NH4^+ ==> NH3 + H2O\
I...0.194.....0.268......0......0
C..-0.194... -0.194....+0.194.....
E.....0.......0.074.....0.194

This ends up being a buffer of NH4Cl/NH3. All of the NaOH is used.
The Henderson-Hasselbalch equation will solve for pH and convert that to OH^-
pH = pKa + log(NH3(/(NH4^+)

Answer 2

Thanks got it!