[Caustikola]

I wanted some HOCl by electrolysis of NaCl and H20 using graphite electrodes. The cathode halfcell was NaCl and the anode half cell was H2O. As expected, i got NaOH at the cathode but i got a dark brown liquid (which smells like HOCl anyway) at the anode. I used a 6V Battery and the cell was run for about 25 hours. My question is 'is HOCl really brown?' i stored the brown liquid in a plastic bottle and after a few days the liquid turned clear and pale yellow and the smell of HOCl was gone

[Arkcon]

I wanted some HOCl by electrolysis of NaCl and H20 using graphite electrodes.

Cool.

The cathode halfcell was NaCl and the anode half cell was H2O.

This part I don't understand.  When constructing a battery, we use half cells, connected by a salt bridge, or other diffusion inhibitor, like a porous cup, or something like that.  We don't use half cells for electrolysis.  Maybe you could draw a diagram, so we can understand what you mean.  Plain water doesn't conduct electricity well enough to be useful for electrolysis.

As expected, i got NaOH at the cathode but i got a dark brown liquid (which smells like HOCl anyway) at the anode. I used a 6V Battery and the cell was run for about 25 hours. My question is 'is HOCl really brown?' i stored the brown liquid in a plastic bottle and after a few days the liquid turned clear and pale yellow and the smell of HOCl was gone

Many different things are happening.  Some other things are described ... incorrectly.  Or your observations are clear, but your explanation isn't.   Maybe.  Or something.  Maybe your electrodes are decomposing?

[Caustikola]

I used two half cells connected with Cotton wool to prevent the solutions from mixing. The cathode becomes negatively charged because of reduction of H2O
2H2O+2e- ---->H2+2OH-
Cl-moves to the cathode under the influence of the curent to ensure that charges are balanced. The Cl- is discharged at the anode. It is possible. Maybe you can experiment it

[Borek]

Such color is usually an effect of the graphite electrode decomposition.

[Caustikola]

Borek
thanks, is the  decomposition a chemical process? What are the products of such decomposition?

[Arkcon]

I used two half cells connected with Cotton wool to prevent the solutions from mixing. The cathode becomes negatively charged because of reduction of H2O
2H2O+2e- ---->H2+2OH-
Cl-moves to the cathode under the influence of the curent to ensure that charges are balanced. The Cl- is discharged at the anode. It is possible. Maybe you can experiment it

I'm sorry, I still don't understand.  Is this a battery: http://en.wikipedia.org/wiki/Electrochemical_cell

Or an electrolytic cell:  http://en.wikipedia.org/wiki/Electrolytic_cell

Can you draw your setup for us?

[Caustikola]

Allright. I'm sorry I can't draw it but it resembles an electrochemical cell except that the two halfcells are connected to a battery.I was reading an article on it in wikipedia:Chloralkali process. I was reading the Laboratory procedure and i followed the steps they gave.