Answer: Ca(OH)2 = Ca2+ + 2 OH-
the ratio between Ca(OH)2 and OH- is 1 : 2
Explanation: [OH-]= 2 x 0.00034 = 0.00068 M
[H+]= Kw/[OH-]= 1.0 x 10^-14 / 0.00068 =1.5 x 10^-11 M ( at two significant figures)
HCl is a monoprotic acid
[H+]= 0.00031 M
[OH-]= Kw/[H+]= 1.0 x 10^-14 / 0.00031 =3.2 x 10^-11 M
[OH-]= 0.047 M
[H+]= 1.0 x 10^-14 / 0.047 =2.1 x 10^-13 M
