Chemistry..URGENT HELP NEEDED!!

[XPFMember]

Assalamoalaikum!!
I have a question about electrolysis...plz help me out..exam's tomorrow!!

Quring the electrolysis of molten Aluminium chloride (AlCl3) the carbon anodes are burned away.Explain why this should happen and write balanced chemical equations for the reactions that take place.

 

[scouserlfc]

TRY ASKING THIS FROM CHEM MASTER HE SHOULD NO THIS.TRY TO PING HIM..

 

[AnGeL.Of.DaRkNeSs]

I GUESS these are the basic reasons why the carbon anode burns away.
1. They have yet to find a cost effective material that will survive the temperatures and corrosive chemical conditions in a melter cell.
2. The burning of the carbon-carbon electrode actually provides some of the chemical energy for the reduction reaction so reducing the amount of electricity for the melting process.
3.Chlorine gas is the anode product, and this reacts with the carbon at the temperature of the electrolysis:
C + 2Cl2 -----> CCl4


BUT i guess u are confused i think the electrolysis i ever heard of Aluminum was the AL203 aluminum oxide in which oxide (from bauxite) was dissolved in molten cryolite. The anode product is oxygen which burns the anode away as CO2

 

[AnGeL.Of.DaRkNeSs]

rest u can ask from chem master he may give a detailed description along with that balanced reaction.

 

[XPFMember]

actually sumbody has asked me this question and it's in the IGCSE Chemistry book..hodder education...a table is given in which we have to fill in the details of some given conditions like product at anode and all that ...even in that they have asked abt aluminium oxide but in this part they asked abt AlCl3 ...i also had a doubt that there is a mistake in the question but b4 saying that the book is wrong i wanted to confirm whether this question has a solution or not
if there's no correct answer then i'll regard the question as a wrong one

 

[Silent Hunter]

they might be burned away due to the removal of gases .............

 

[XPFMember]

but that's nt the case only with Aluminium chloride...if this was the reason then it should be for every other reaction too???

 

[AnGeL.Of.DaRkNeSs]

well mathangel basic rule for burning away of anodes is that if electrolyte contain metal ion of which anode is made anode dissolves