Chemistry 9701 · AS & A Level · Chemistry of transition elements

Chemistry of transition elements — practice question

Transition elements are important metals because they have characteristic properties.
(a)[1]

Define what the term transition element means.

(b(i))[2]

For each of the complexes below, state the co-ordination number and the oxidation number of the transition element present:\n$[\text{Ni(CN)}_2(\text{NH}_3)_2]$\n$[\text{CrCl}_2(\text{H}_2\text{O})_4]^+$.

(b(ii))[1]

State the kind of bonding present between the ligand and the metal ion in these complexes.

(b(iii))[2]

Suggest the structure of $[\text{Ni(CN)}_2(\text{NH}_3)_2]$ and give its shape.

(c(i))[1]

The complex ion $[\text{Cr(H}_2\text{O})_6]^{3+}$ can be changed into $[\text{CrCl}_2(\text{H}_2\text{O})_4]^+$. Suggest a suitable reagent for this conversion.

(c(ii))[1]

State the type of reaction shown in part (c)(i).

(d(i))[1]

The $[\text{CrCl}_2(\text{H}_2\text{O})_4]^+$ complex ion shows stereoisomerism. Name this form of stereoisomerism.

(d(ii))[3]

Draw 3D diagrams to show the two stereoisomers of $[\text{CrCl}_2(\text{H}_2\text{O})_4]^+$.

Worked solution & mark scheme

This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: An element that forms one or more stable ions with an incomplete $d$ subshell.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI