Question

The coordination number of zinc in zinc blende $\left( {ZnS} \right)$ is _________
A: $6$
B: $4$
C: $8$
D: $12$

Answer 1

Hint : Coordination number is the number of atoms or ions surrounding a central atom in a complex or crystal structure. Zinc blende has face centered cubic close packing(FCC). This packing has $4$ atoms per unit cell.

Complete step by step solution :
The process of electrorefining impure metal is made as anode and a thin strip of same pure metal is made as cathode. Solution of metal ions is used as an electrolyte. When current is passed an equivalent amount of pure metal from the anode gets oxidized to cathode. After a certain period of time all pure metal is collected on cathode and insoluble impurities are left behind on anode whereas soluble impurities get dissolved in electrolyte so the correct option is A anode.
Additional information: Electrorefining is the finest way of purification and gets pure metal. Many metals like $Cu,Sn,Ni,Ag,Au$ etc can be purified with this method.
In this method Redox reaction takes place at the respective position of anode and cathode.
At anode oxidation of metal occurs
At cathode reduction reaction takes place
It is also a commercially applicable method to purify metals on a large scale. It should be remembered that the electrolyte that we have taken in the process should be salt of that particular metal that we are trying to purify. An electrolyte should bear the qualities such that it can completely dissociate or ionize because such electrolytes are good conductors of electricity hence improves the efficiency of the process.
Some of the natural electrolytes present in our day to day life are coconut water, milk, watermelon water, sports drinks. Most of the alkali and alkaline earth metal salts are strong electrolytes.
Hence, Option A is the correct answer.

Note : Remember at anode oxidation reaction occurs and at cathode reduction reaction occurs. Anode is negative whereas cathode is positive. Remember electrodes which will be consumed are made of impure metal (at anode) on the other hand electrodes on which metal will be deposited will contain strips of pure metal (at cathode).