On dissociation,  Cu(IO\(_3\))\(_2\) ⇌ Cu\(^{2+}\)(aq) + 2IO\(_3\)\(^-\)(aq). 

Solubility product constant = Ksp

The formula is : Ksp =  [Cu\(^{2+}\)] [IO\(_3\)\(^-\)]\(^2\)

Let the concentrations of Cu\(^{2+}\) and IO\(_3\)\(^-\)  be expressed as d.

[Cu\(^{2+}\)] = d  ; [ IO\(_3\)\(^-\)] = 2d (because 2IO\(_3\)\(^-\) )

Substituting these expressions into the Ksp

Ksp =  [Cu\(^{2+}\)] [IO\(_3\)\(^-\)]\(^2\)

Ksp = (d) x (2d)\(^2\)

Ksp = d.4d\(^2\)

Ksp = 4d\(^3\)

Recall that Ksp = 1.08 x 10\(^{-7}\)

4d\(^3\) = 1.08 x 10\(^{-7}\)

Divide both sides by 4

d\(^3\) = \(\frac{1.08 x 10^{-7}}{4}\)

d\(^3\) = 0.000000027

d = ∛0.000 000 027

d = 0.003

d = 3 x 10\(^{-3}\) moldm\(^{-3}\)