M3A2 is a sparingly soluble salt of molar mass y g mol-1 and solubility x g L-1. The ratio of the molar concentration of the anion ( A3-) to the solubility product of the salt is
- 154 y4x4
- y5108x4
- 108 x5y5
- 1108 y4x4
Answer
(1) 154 y4x4
Solution
The molar solubility is s = xy mol L-1.
From M3A2(s) 3M2+(aq) + 2A3-(aq), [ M2+] = 3s and [ A3-] = 2s, so
Ksp = (3s)3(2s)2 = 108s5
[ A3-]Ksp = 2s108s5 = 154s4
∴ [ A3-]Ksp = 154 y4x4
Answer: (1)