Consider an aqueous solution Ba^+2 (0.05M) and Pb^+2 (0.30M) BaCO3(s) <------> B
ID: 886942 • Letter: C
Question
Consider an aqueous solution Ba^+2 (0.05M) and Pb^+2 (0.30M)
BaCO3(s) <------> Ba^2+ (aq) + CO3^2- Ksp=5.0x10^-9
PbCO3(s) <------> Pb^2+ (aq) + CO3^2- (aq) Ksp=7.4x10^-14
a) write three independent mathematical equilibrium constant equations related this solution
b) Write a cahrge balance equation /expression for the overall solution gerenrated.
c) what is the underlying principle/concept that allows a charge balance equation /expression to be written for a solution?
d) what is the underlying physical concept that allows for the writing of mass balance expresiion when solving simultaneous equilibrium problems?
Explanation / Answer
(a)
Eqn 1 - Ksp(BaCO3) = [Ba2+][CO3^2-]
Eqn 2 - Ksp(PbCO3) = [Pb2+][CO3^2-]
Eqn 3 - Ksp(BaCO3) * Ksp(PbCO3) = [Ba2+][Pb2+][CO3^2-]^2
(b) Charge balance equation for overall solution
BaCO3 + PbCO3 -------> Ba2+ + Pb2+ + 2CO3^2-
(c) Concept is that both sides of the reaction should have the same charge i.e charge should be balanced
(d) Mass balance expression is written similarly as charge but in this case the mass is conserved i.e mass of the reactants = mass of products