Electrolysis

What’s electrolysis?

process that splits ionic compounds into their different elements

How are electrolytes formed?

• when ionic compounds are melted or dissolved in water,

• the ions are free to move around and the solution will conduct electricity

What’s an electroli

• Ionic compounds that dissolve in water

• to make a solution that conducts electricity are called electrolytes

What happens at the electrodes?

• When a voltage (direct current) is applied across an electrolyte

• the charged ions are attracted to the electrode with the opposite charge to the ion

• Positively charged ions move to the negative electrode

• Negatively charged ions move to the positive electrode

What is the negative electrode?

Cathode

What’s the positive electrode?

Anode

What are ionic compounds?

• When simple ionic compounds are heated

• they will eventually melt

What are molten ionic compounds?

• The metal and non metal ions within the molten ionic compound become free to move

• so the liquid can undergo electrolysis

Where will the metal form?

At the negative electrode

Where will the non metal form?

At the positive electrode

How is electrolysis used to extract ores?

• used to extract reactive metals from molten ores

• these metals are more reactive than carbon

What forms at the anode when extracting ores?

• Oxygen forms at the anode

• which reacts with the carbon anode to form carbon dioxide

Why is the anode usually made of carbon?

It is a good conductor and is cheap

What are the disadvantages of electrolysis?

-lots of energy is needed to:

• melt the solid ionic compound to allow the ions to flow

• to produce the electrical current

  -All this energy costs a lot of money