The solubility of (A₂ X₃ ) is ' (y ) ' M. Its solubility product is ( M ^5 ).

Step-by-step solution

For a sparingly soluble salt of molecular formula (A₂ X₃ ), if solubility in pure water is (y M ) at a given temperature, ( aligned A₂ X₃ & 2 A³⁺+3 X²⁻ & 2 y M 3 y M aligned ) Solubility product, (K_ sp = [A³⁺ ]^2 [X²⁻ ]^3=(2 y)^2+(3 y)^3 ) (=4 y^2+27 y^3=108 y^5 M ^5 )