Solid Ca3(PO4)2 is placed into 10.0 L of water. When equilibrium is established, the concentration of Ca+ is 2.3 x 10-4 M. What is Kc for this equilibrium? Ca3(PO4)2 (s) 3 Ca+ (aq) + 2 PO4- (aq) A) 7.7 Correct. 10-5 B) 3.5 10-8 C) 2.7 x 10-19 D) 7.2 x 10-20