I missed this day in class when my teacher went over the Kb and Ka values. How would I calculate the molar concentration of this question? Do I need an ICE chart and what values would I put where?
Calculate the molar concentration of OH - ions in an 1.32 M solution of hypobromite ion, BrO- (Kb = 4.0 10-6).
2007-10-26 09:30:56 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
Write the balanced ionic equation
BrO- + H-OH ---> BrOH + OH-
Write the expression for Kb
Kb = [BrOH][OH-] / [BrO-] (you can leave out the concentration of H2O, since it is already incorporated in the Kb, and doesn't change very much in a water solution.
[BrOH] = [OH-], so use [OH-]^2
[OH-]^2 = Kb x [BrO-]
[OH-] = sq rt (4.0 x 10^-6)(1.32mol/L) ~ 4.3 x 10^3-mol/L OH-
2007-10-26 10:07:18 · answer #1 · answered by papastolte 6 · 0⤊ 0⤋
OBr- + H2O ===> HOBr + OH-
Kb = [HOBr][OH-]/[BrO-] = 4 x 10^-6
Let [HOBr] = [OH-] = x
x^2/(1.32) = 4 x 10^-6
x^2 = 5.28 x 10^-6
x = 2.30 x 10^-3
2007-10-26 10:26:05 · answer #2 · answered by steve_geo1 7 · 0⤊ 0⤋