Posted by L.Bianchessi on Monday, March 5, 2012 at 3:47pm.
A 0.035 M solution of a weak base has a pH of 10.88. What is the Kb for the acid?
Where Di I even begun**???

Chemistry  DrBob222, Monday, March 5, 2012 at 4:00pm
You ALWAYS start with one or all of the following:
1. balanced equation
2. ICE chart
3. think in terms of mols.
pH = 10.88 so pOH = 3.12 and OH^ = 7.58E4
M..........BOH ==> B^+ + OH^
initial.0.035M.....0......0
change..7.58E4..7.58E4..7.58E4
equil..0.0357.58E4....etc
Kb = (B^+)(OH^)/(BOH)
Substitute from the ICE chart and solve for Kb. Note that 0.0357.58E4 is not = 0.035