6. Calculate the pH of a 1.5 x 10-7 M solution of Sr(OH)2, a strong base.
Now that we know that we need to consider the dissociation of water, we need to calculate how the water will respond once the Sr(OH)2 has dissociated. The ionization equilibrium for water is

H2O (l) H+ (aq) + OH- (aq)

Now we must identify the INITIAL concentrations, determine the change in concentration and find the equilibrium concentrations of each species. We do this with an I.C.E. table:

H2O (l) H+ (aq) OH- (aq)
INITIAL
-
CHANGE
-
EQUILIBRIUM
-

What are the initial concentrations of the aqueous species?

a) 0M, 0M
b) 0M, 3.0x10-7M
c) 3.0x10-7M, 3.0x10-7M
d) 1.0x10-7M, 3.0x10-7M