Hellppp (1 Viewer)

[zeee1999]

Sorry if this is a dumb question but how would this be solved:

"Calculate the hydroxide ion concentration of a solution of potassium hydroxide with a pH of 9"

 

[OkDen]

KOH --> K + OH

pH+pOH = 14
pOH = 14 - pH
= 14 - 9
= 5

[OH-] = 10^-pOH
= 10^-5
= 0.00001M

 

[Robbie M]

Yeah or an easier way is
10^-9 = [hydronium concentration]
1 x 10^-14 = [h3O+] x [OH-]
1 x 10^-14 / 10^-9
Thus 0.00001M = OH-