## Chemistry: The Molecular Science (5th Edition)

$1 Cd^{2+}(aq) + 4 NH_3(aq) \lt -- \gt 1 [Cd(NH_3)_4]^{2+}$ $K_f = \frac{[[Cd(NH_3)_4]^{2+}]^1}{[Cd^{2+}]^1[NH_3]^4}$
1. Identify the separate compounds and their quantities in this complex ion: - 1 $Cd^{2+}$ - 4 $NH_3$ 2. Write the equation where they combine to formate the complex ion $[Cd(NH_3)_4]^{2+}$ $1 Cd^{2+}(aq) + 4 NH_3(aq) \lt -- \gt 1 [Cd(NH_3)_4]^{2+}$ 3. Write the formation constant expression: - It will be: the concentrations of the products divided by that of the reactants: - And remember: the balance coefficients will be the exponents of their concentrations. $K_f = \frac{[Products]}{[Reactants]}$ $K_f = \frac{[[Cd(NH_3)_4]^{2+}]^1}{[Cd^{2+}]^1[NH_3]^4}$