Define transition element.

1. (a)(i)Define transition element.[1]
2. (a)(ii)Explain why transition elements can form complex ions.[1]
3. (b)(i)The 3d orbitals in an isolated Ag⁺ ion are degenerate. Define degenerate d orbitals.[1]
4. (b)(ii)Sketch the shape of a 3dxy orbital in Fig. 2.1. [Figure 2.1][1]
5. (c)Tollens' reagent can be used to distinguish between aldehydes and ketones. Tollens' reagent contains [Ag(NH₃)₂]OH, which can be prepared in a two-step process. step 1 Aqueous NaOH is added dropwise to aqueous AgNO₃ to form Ag₂O as a brown precipitate. step 2 Aqueous NH₃ is added dropwise to Ag₂O to form a colourless solution containing [Ag(NH₃)₂]OH. Construct equations for each of the steps in the preparation of [Ag(NH₃)₂]OH. step 1 step 2[2]
6. (d)Name the shape of the complex ion [Ag(NH₃)₂]⁺. State the bond angle for H-N-Ag and for N-Ag-N. shape bond angle for H-N-Ag = bond angle for N-Ag-N =[2]
7. (e)An electrochemical cell uses Ag₂O as the positive electrode and Zn as the negative electrode immersed in an alkaline electrolyte. The overall cell reaction is shown. Ag₂O + Zn + H₂O → 2Ag + Zn(OH)₂ Complete the half-equation for the reaction at each electrode. at the positive electrode Ag₂O + at the negative electrode Zn +[2]
8. (f)Coordination polymers are made when a bidentate ligand acts as a bridge between different metal ions. Under certain conditions Ru³⁺(aq) and the bidentate ligand dps can form a coordination polymer containing ([Ru(dps)Cl₄]⁻)n chains. [Figure 2.2] The bidentate ligand dps uses each of the nitrogen atoms to bond to a different Ru³⁺. Complete Fig. 2.3 by drawing the structure for the coordination polymer ([Ru(dps)Cl₄]⁻)n. Show two repeat units. The dps ligand can be represented using N N. [Figure 2.3][2]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.