Electrolysis of water(ion and electrode)

1. Aug 8, 2012

kevin_tee

I'm new to this forum, I am studying in grade 9 and I am working on my electrolysis project but I had trouble understanding about ion and electrode (this is not my homework, I just don't understand) why does positive ion attract to negative electrode, I know that positive should attract negative, but what king of force does the electrode emitting, because electrolysis is just adding some current to the electrode, so it is just a flow of electrons, negative is emitting electrons and positive is taking electrons so actually both electrode had an electrons. Why is positive ion is flowing against the flowing of electrons. If the electrode is emitting any kind of force field what is happening in side the electrode? Thank for every comments.

2. Aug 8, 2012

Amok

I'm having a hard time understanding your question. Can you try to formulate it in a clearer fashion? Anyway, the force involved in attracting ions to electrodes is always electric. If an electrode has an electron defficiency, it will be positively charged and hence attract anions. The opposite is also true.

3. Aug 8, 2012

kevin_tee

so the force attracting ions is electric field? Why does flowing of electron create an electric field?
I know that electron emit an electric field, but both electrode has electron so why one end is positive and another end is negative?

Last edited: Aug 8, 2012
4. Aug 9, 2012

Amok

Well, electrons are flowing from one electrode to the other, so one of them is going to have a net defficiency of electrons and a surplus of positive charges (from hydrogen I think). The other electrode is gonna receive electrons and thus have a surplus of electrons (which leads to the formations of hyrdoxy anions, if I'm not mistaken) and therefore have a negative total charge.

In every electrode there are atoms, which have both electrons (negative) and protons (positive). If you take electrons away from the atoms in the first electrode and give them to the atoms in the second electrode, then the atoms in the first electrode are gonna become postively charged and vice-versa.

5. Aug 9, 2012

Staff: Mentor

When you start your electrolysis you apply a voltage to your electrodes. This causes one of them to be positively charged and one to be negatively charged. If there were no electrolyte in between them then no current would flow and nothing would happen. However because the electrolyte conducts electricity we get a flow of current between the two electrodes. The electrolyte is completing the circuit between the two electrodes, just like normal water can do to a normal circuit or electronic device. (Which generally causes a short to occur)

Now, in a normal circuit made of wires, the positive ions cannot move as they are the nuclei of the atoms in the metal and are stuck in place. Thus only the electrons move around. However in an electrolyte positive ions CAN move because the electrolyte is a liquid, not a solid. So you can have electrons moving from the cathode(-) to the anode(+), and ions moving from the anode to the cathode.

The flowing of electrons doesn't create an electric field. The field is caused by your power source for the circuit creating a voltage, which is a difference in electrical potential between two spots. If you connect the terminals of a battery together a current will flow because one terminal is + and the other is - and will send electrons through your circuit from the - terminal to the + terminal. The way this voltage is generated is actually the reverse of electrolysis. (Just for a battery, not for generators and other ways of producing electrical power)

6. Aug 9, 2012

kevin_tee

Does it mean that on the negative electrode side there are more electron gathering there?

7. Aug 9, 2012

Staff: Mentor

The negative electrode acts as the source of electrons to give to the positive ions. It is where they electrons enter the electrolyte at. The positive electrode is where the electrons leave the electrolyte and enter the rest of the circuit. The total number of electrons in the electrons remains the same because while you have some entering from the negative electrode you have an equal number leaving at the positive electrode.