Answer:
[tex]s= 5.9*10^{-4} M[/tex]
Explanation:
Solubility is s.
[tex]Ca(OH)_{2} --> Ca^{2+} +2OH^{-}\\[/tex]
s 2s
[tex]K_{sp}= [Ca^{2+}][OH^{-}]^{2}[/tex]
[tex]K_{sp} = s*(2s)^{2}[/tex]
When we have Ca(OH)2 in Na(OH) solution, because NaOH has OH- also :
[tex]K_{sp}=s*(2s+0.047)^{2}[/tex],
because 2s << 0.047,
we can write
[tex]K_{sp} = s*0.047^{2}\\\\1.3*10^{-6}=s*0.047^{2}\\\\s= 5.9*10^{-4} M[/tex]
