Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: j9sully on 20/04/2004 18:31:04

Title: Electrolysis
Post by: j9sully on 20/04/2004 18:31:04

I need to explain what would occur when the following substances are electrolysed:

molten Kbr
molten Al(2)O(3)
Nal solution
dilute sulphuric acid

i know they split, one goes to anode, one to cathode but i think one or two of them leave a substance free.......any help would be welcome

Many thanks

Title: Re: Electrolysis
Post by: CsManiacDan on 20/04/2004 20:43:51

Hi J9sully!

Correct me if i'm wrong but i think this is what KBr would do:

Potassium has a valency of +1 so it goes to the negative electrode (cathode), the bromine would go to the other.

Al(2)O(3)
The aluminium has a +3 Valency so would go to the Cathode and the oxygen would go to the anode.

The Nal I assume means NaCl
Sodium has a valency of +1 so would go to the Cathode and The chlorine would go to anode

That's all I'm sure and it's been a while since I did this so if anyone knows better please feel free to point it out!

I Love Caesium!!!

Title: Re: Electrolysis
Post by: ruthenium on 20/04/2004 21:06:07

About dilute sulphiric acid, on Cathode would develop hydrogen, on Anode xygen

Title: Re: Electrolysis
Post by: j9sully on 21/04/2004 13:54:30

Thanking you both for your very valuable replies....it all makes complete sense and has done me a huge favour....thanks again!!!

[8D]

Title: Re: Electrolysis
Post by: nilmot on 21/04/2004 14:00:24

I think depend on the electrodes you use the product formed might be different. Like with O2 moves toward the anode, if anode is made of carbon, then CO2 will be produced. Or I could be just talking ____ here

Tom

Title: Re: Electrolysis
Post by: chris on 21/04/2004 23:50:59

Yeah, you're a bit confused there. You'll only make CO2 in the presence of oxygen if the temperature is sufficiently high to make the two react. At room temperature the carbon is inert and the oxygen is released as bubbles.

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx

Title: Re: Electrolysis
Post by: nilmot on 22/04/2004 10:49:55

Mmm...but if you are to get aluminium oxide molten , won't the temperature be high , very high in the first place anyway?

Tom

Title: Re: Electrolysis
Post by: cuso4 on 22/04/2004 11:45:58

Yep very high. About 2000 degrees C. Cryolite (sodium aluminium fluoride, Na3AlF6) act as a solvent in Al2O3 and reduce the melting point to about 1000 degrees C.

Angel

Title: Re: Electrolysis
Post by: taylorjdfan on 22/04/2004 17:26:32

Hey, i fault i had a reply then n got al xcited!!!

I aint having n e luck either!!! Dont fink it will b dun by 2muro, how much u dun!!!!