Hi, was wondering if anyone out there could help me with this acids/bases problem I'm stumped on: The equilibrium constant for dissolving CaCO3 in water is 3.4E-9. What is the equilibrium constant for dissolving CaCO3 in the presence of acid? (Ka of H2CO3 = 4.2E-7; Ka of HCO3- = 4.8E-11) a. 1.6E-19 b. 2.9E8 c. .008 d. 70.8 The correct answer is d. I am confused about how to even approach this problem, or make use of the information being given. Also, the Ka for CO3^2- is 2.1E-4, not 3.4E-9, so I'm not even sure where that number comes from... Any help would be greatly appreciated.