Solubility of calcium phosphate (molecular mass, M) in water is W g per 100 mL at 250C. Its solubility product at 250C will be approximately

S =M= 10 WM  mol/L Ca3(PO4)2⇌3Ca+2+2PO4-2                       3s           2s KSP of Ca3 PO42 = 108 S5 = 108 10WM5 = 107 WM5   approximately