This question is about the industrial separation of precious metals

When nickel or copper are purified by electrolysis the impurities are deposited below the anode as

the impurities are deposited below the anode 'anode sludge'. The impurities include the rare metals ruthenium, osmium, rhodium, iridium,

metals ruthenium, osmium, rhodium, indium, palladium, platinum, silver and gold.

$($a$)$ Identify which element is responsible for each of the electronic structures:

$($i$)[Kr]4d^{10}$

$($iii$)[xe]4f^{14}5d^{7}6s^2$

The metal impurities are initially separated by adding aqua regia $(HC\frac{l}{H}N{O}_3).$ Gold, palladium

and platinum form soluble complexes. Other metals are precipitated as elements and insoluble

The gold and platinum react with the aqua regia to form sol and chloroplatinic acid $(H_{2}PtCl),$ as well as nitrogen dioxide.

$($b$)($i$)$ Write an equation for the reaction of gold with aqua regia

$($ii$)$ Write an equation for the reaction of platinum with aqua regia.

Mass spectrometry can be used to identify the chloroauric acid. Naturally occurring chlorine exists as two isotopes abundance$)$ and abundance$).{?}^{197}Au$ is $100\%$

$($c$)$ Calculate the $\frac{m}{z}$ values and intensities of the molecular ion peaks for the $AuC{l}_4^{-}$ion as

Gold is precipitated out of the mixture by adding iron$($II$)$ chloride. This leaves the chloroplatinic acid and chloropalladic acid in solution. The addition of ammonium chloride leads

chloroplatinic acid and chloropalladic acid in solution. The addition of ammonium chloride leads to the precipitation of Compound $x.$ Following this, the addition of ammonium hydroxide leads to the precipitation of Compound $Y$

$($d$)$ Write an equation for the reaction of chloroauric acid with iron$($II$)$ chloride.

A unit cell is determined by $x-$ray crystallography. The unit cell shows the arrangement of atoms in a crystal. Stacking the unit cells together generates the bulk structure.

The diagram shows the unit cell of

corners and contres of the faces of the un

bonded to the chloride ligands. Some of

the boundaries of a single unit cell. Only a

edges, or faces are contained within a

$($e$)$ What is the formula of compound $x$

Compound $Y$ contains $Pd$ in a square planar environment.

Elemental analysis reveals: $Pd50\mathrm{.}3\%,Cl33\mathrm{.}5\%,N13\mathrm{.}3\%$ and $H2\mathrm{.}9\%.$

$($f$)$ Draw the possible structures of compound $Y$

$($g$)$ Write an equation for the formation of compound $Y$ from $H_{2}PdCl.$

Transition metal complexes can be identified using a range of spectroscopic techniques, one of

which is nuclear magnetic resonance $($NMR$).$ Just as $1H$ and ${?}^{1}CC$ nuclei can be excited in an NMR experiment, so can transition metal nucle. An NMR spectrum can be run if the spin $(I)$ is

not zero. Nuclei such as ${?}^{105}Pt$ and ${?}^{100}Rh$ give useful spectra, however, o ${?}_{10}PPd$ lead to very broad lines and are unsuitable for NMR experiments.

Coupling of transition metal nuclei to other nuclei can cause signals to split, similar to the doublets, triplets and quartets seen in ${?}^{1}HNMR.$

Number of peaks into which the resonance is split $=(2NI)+1$

where $N=$ number of equivalent nucle

$I=$ spin of nuclei coupled to

$195Pt$ has spin $I=\frac{1}{2^1}H$ can be considered as $100\%$ abundant and has spin $I=\frac{1}{2.{?}^{16}}O$ can be considered as $100\%$ abundant and has spin $I=0.{?}^{1}H$ nuclei are not seen to couple to the

considered as $100\%$ abu platinum in ${?}^{155}PtNMR.$

$-2576$ and $-1555ppm.$ These signals are split because the platinum nuclei couple to either

$($h$)$ Calculate the number of lines the ${?}^{130Pt}$ signal is split into by nitrogen in the ${?}^{195Pt}NMR$ of:

$($i$)$

$($ii$)[P{t}^{13}N{H}_3{)}_4$

$($iii$)$