What is the pH of a 1.00 x 10^-4 M solution of lithium hydroxide solution?

1 Answer
Sep 6, 2016

Answer:

#pH=10#

Explanation:

#pH#, #"pouvoir hydrogene"#, #=-log_10[H_3O^+]#

Now it is a fact that in water the following autoprotolysis takes place:

#2H_2O(l) rightleftharpoonsHO^(-) + H_3O^+#

The ionic product at #298*K# #=# #K_w=[H_3O^+][HO^-]=10^-14#.

If we take #-log_10# of both sides we get:

#pK_w =14=-log_10[H_3O^+]-log_10[HO^-]#

But by definition, #pH =-log_10[H_3O^+]# and #pOH =-log_10[HO^-]#

Thus #pK_w =14=pH+pOH#

And so #pOH# #=# #-log_10(10^-4)# #=# #4#

And #pH=10#.

Capisce?