[ketanof92]

I am doing an experiment involving water electrolysis for science fair. I am trying to test how heat affects water electrolysis but I am getting very strange observations in my experiment.
In my setup i am using NaCl Solution, 9 volt batteries and some wire which i know nothing about. It is silverish in color but i don't know what metal it is.
During the experiment, gas is only evolved at the cathode, I believe the gas is hydrogen. By the end of the experiment the anode has changed color to copperish (it may not be copper it just that color). Also there is somekind of greenish yellowish liquid on the anode.
Any idea what is happening.

[Borek]

Have you tested the gas? You better start with a solution containing NaOH or H₂SO₄, not NaCl. And look for graphite electrodes.

I believe woelen wrote on the subject more then once, but I am not sure if he did it on chemicalforums or somewhere else. Search forums for water electrolysis.

[constant thinker]

You can get graphite rods from old lithium lantern batteries. Just do a search, it's easy to find.

I think woelen did post something about electrolysis somewhere on the forums.

[kitfat2001]

just give my little opinions~
i agree with Borek.
you better use NaOH or H2SO4.
When NaCl solution is dilute, H2O will be decomposed during electolysis because the OH- in H2O more likely to carry out oxidation than Cl-.
However, when electrolysis has been carrying for some times, the NaCl solution become concentrated because water is decomposed in to O2 and H2.
At that time, Cl- will more likely to carry out oxidation than OH- because of the concentration effect
So Cl2 will form.

**P.S. If i have get something wrong, please notice me. THANKS