Answer:
AgI, AgBr, AgCl and Ag₂CrO₄
Explanation:
Ksp (product solubility constant) is defined as the equilibrium constant of the general reaction:
XₐYₙ(s) → aXⁿ⁺(aq) + nYᵃ⁻(aq)
Where X is cation and Y is anion.
Ksp = [aXⁿ⁺]ᵃ [nYᵃ⁻]ⁿ
The presence of XₐYₙ(s) produce ax moles of aXⁿ⁺ and nx moles of Yᵃ⁻. Where X is the solubility of the compound.
Replacing in Ksp:
Ksp = [ax]ᵃ [nx]ⁿ
Solving for x, Solubility (S) is defined as:
[tex]S = \sqrt[n+a]{\frac{Ksp}{a^{a} n^n} }[/tex]
For AgCl, Ag₂CrO₄, AgBr and AgI solubilities are:
[tex]S = \sqrt[2]{\frac{1.8x10^{-10}}{1} }[/tex] = 1.34x10⁻⁵M
[tex]S = \sqrt[3]{\frac{1.1x10^{-12}}{4} }[/tex] = 6.50x10⁻⁵M
[tex]S = \sqrt[2]{\frac{5.4x10^{-13}}{1} }[/tex] = 7.35x10⁻⁷M
[tex]S = \sqrt[2]{\frac{8.5^{-17}}{1} }[/tex] = 9.22x10⁻⁹M
The lower solubility is the first compound in precipitate, thus, order of precipitation is:
AgI, AgBr, AgCl and Ag₂CrO₄
