How the Rate of Electrolysis is Affected by Changing the Current in the Circuit

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How the Rate of Electrolysis is Affected by Changing the Current in the Circuit

When chemical compounds are in a molten state, or if they are

dissolved in water or other liquids their molecules become "separates

into positively and negatively charged components, which have the

conduct electricity", or they become ionized

[IMAGE]Electrolysis is the process of breaking down or 'decomposing' a

compound, by running an electric current through a chemical compound

when it is ionized. This is done using a simple circuit, as below:


When a pair of electrodes as above is placed in an ionized solution

(Electrolyte) and there is a current flowing between them, the

positive ions move toward the negative electrode - cathode and the

negative ions move towards the positive electrode - anode. The ions

that move towards the cathode are called "cations" and the ions that

move toward the anode are called "anions". When the ions reach their

respective electrodes, they gain or lose electrons and are transformed

into neutral atoms.

Electrolysis of molten lead bromide:


The electrolyte is Molten Lead Bromide

As is above, the ions gain or lose electrons at the electrodes. These

reactions can be shown using "Half - Equation". Below, I have shown

them using the example of Lead Bromide.

[IMAGE]The lead bromide is separated into molten lead and Bromide.

PbBr(l) Pb(l) + Br²(g)

When lead Bromide is melted, the ions are free to move towards the

oppositely charged electrode, because Lead Bromide is an ionic


[IMAGE]When the positive lead ions move to the negative electrode,

they gain electrons in a reduction reaction: Pb²+ + 2e- Pb

[IMAGE]In the same way when the negative bromide ions move to the

positive electrode they lose electrons in an oxidation reaction

2Br- - 2e- Br²

Sometimes oxidation reactions are written with "+2e-" on the left.

[IMAGE]In such instances the alternative half equation is:

2Br- Br² + 2e-

Electrolysis - How Does It Happen?

A compound made from metal and non-metal has ions which cannot move

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