Fill in the missing parts of these electronic structures: • iron atom, Fe: $1s^2 2s^2 2p^6 \,\ldots$ • iron(III) ion, $\text{Fe}^{3+}$: $1s^2 2s^2 2p^6 \,\ldots$
Solutions of iron(III) salts are acidic because of the equilibrium below. $[\text{Fe(H}_2\text{O)}_6]^{3+}(\text{aq}) \rightleftharpoons [\text{Fe(H}_2\text{O)}_5(\text{OH})]^{2+}(\text{aq}) + \text{H}^+(\text{aq})$ $K_a = 8.9 \times 10^{-4}\,\text{mol dm}^{-3}$ Calculate the pH of a $0.25\,\text{mol dm}^{-3}$ FeCl$_3$ solution.
What does the term stability constant, $K_{\text{stab}}$, mean?
Use the table data to predict the formula of the complex formed in the greatest amount when: • a solution containing equal concentrations of both $\text{F}^-$ and $\text{SCN}^-$ ions is added to $\text{Fe}^{3+}(\text{aq})$; • a solution containing equal concentrations of both $\text{Fe}^{3+}$ and $\text{Hg}^{2+}$ ions is added to $\text{Cl}^-(\text{aq})$.
The complex $[\text{Fe(ed)}_2\text{Cl}_2]^{3-}$ can be produced by the equation shown. $[\text{Fe(H}_2\text{O)}_4\text{Cl}_2]^+(aq) + 2\,\text{ed}^{2-}(aq) \rightleftharpoons [\text{Fe(ed)}_2\text{Cl}_2]^{3-}(aq) + 4\,\text{H}_2\text{O}(l)$. Write the expression for the equilibrium constant, $K_{\text{stab}}$, and state its units.
$[\text{Fe(ed)}_2\text{Cl}_2]^{3-}$ shows geometrical and optical isomerism. Complete the three-dimensional diagrams to display the three stereoisomers of $[\text{Fe(ed)}_2\text{Cl}_2]^{3-}$. You may use -O-O- to stand for $\text{ed}^{2-}$.
State the letters of two isomers of $[\text{Fe(ed)}_2\text{Cl}_2]^{3-}$ that are geometrical isomers of one another.
State the letters of the two isomers of $[\text{Fe(ed)}_2\text{Cl}_2]^{3-}$ that display optical isomerism.
State the letter of the isomer with no dipole moment.