For the complex formation reaction where M is any metal and L is any ligand, M++
ID: 520143 • Letter: F
Question
For the complex formation reaction where M is any metal and L is any ligand,
M++2L[ML2]+
Kf is the formation constant for the complex at equilibrium and G is the Gibbs free energy change for the reaction at equilibrium.The formation constant (Kf) can be related to the Gibbs free energy change (G) for a reaction by the equation
G=RTln Kf
where T is the temperature in kelvins and R is the gas constant equal to 8.314 JK1mol1. The complex formation is generally a spontaneous process; thus, the Gibbs free energy change is negative.
Calculate the formation constant for the formation of [Cu(NH3)2(H2O)4]2+ from [Cu(H2O)6]2+, given that G is 44.7kJmol1 at 298 K.
Express your answer numerically to three significant figures.
Explanation / Answer
G = 44.7kJmol1
G=RTln Kf
- 44.7 = - 8.314 x 10^-3 x 298 x ln Kf
Kf = 6.85 x 10^7
Kf = 6.85 x 10^7