Electrolysis

Electrolysis

Multiple Choice

What is an ore?

• a rock that contains metal oxides which can be extracted

• something to paddle a canoe

• an extracted, purified metal

• I don't know

Open Ended

Name a metal that is not found as an ore.

Multiple Choice

is pH acid, alkali or neutral?

• acid

• alkali

• neutral

Multiple Choice

What is the most reactive metal in the reactivity series?

• Potassium

• Magnesium

• Copper

• Lithium

Multiple Choice

Why can't you use carbon to separate aluminium from its ore?

• Aluminium is less reactive than carbon

• aluminium is more reactive than carbon

• carbon is inert (it won't react)

• I don't know

Multiple Choice

Will this reaction take place?

Carbon + Copper oxide -----> copper + carbon dioxide

• yes

• no

• I don't know

Molten electrolysis

• Explain why some metals need to be extracted by hydrolysis

• Describe the process of hydrolysis

• Explain the movement of ions during electrolysis

Keywords - copy these into your books

• Cation - a positively charged ion

• Anion - a negatively charged ion

• Electrolysis - the splitting of a substance using electricity

• Molten - a substance liquified by heat (turned from a solid to a liquid)

Decode: Electrolysis

(copy the word and definition)

• Definition: The breaking down of a substance by passing an electric current through it.

• it is a process used in industry, the beauty industry (hair removal), Jewellery making (gold and silver plating) and in medicine

Reactivity series

How reactive a metal is determines the method we use to extract it.

Electrolysis

The group 1 metals are separated using Electrolysis.

This is where metals are extracted using electricity

Smelting

As the metals become less reactive, we use a process called 'smelting'.

Carbon is used to remove the oxygen and leave the metal behind

least reactive metals

The least reactive metals usually appear as chunks of metal - they are usually quite pure

Multiple Choice

What do you call a metal which doesn't react?

• inert

• asleep

• uninterested

• waiting

Electrolysis

the flow of electrons in a a conducting solution or molten liquid which causes chemical changes.

A molten liquid is usually an substance that has been heated so high that it liquifies (becomes a liquid)

The conducting liquid is called an electrolyte and has free moving ions in it.

Positively charged ions are: Anions

Negatively charges ions are: Cations

Electrodes

two pieces of metal are placed inside the conducting solution.

These are called electrodes and can be connected to an electrical charge.

Multiple Choice

What is the name of the the negatively charged ions?

• anions

• cations

Electrodes

The electrodes attract the oppositely charged ions to themselves (remember - like charges repel opposites attract)

The positive electrode is called the Anode and attracts Cations

The negative electrode is the Cathode and attracts Anions

Anode/Cathode

Don't PANIC!

Positive

Anode

Negative

Is

Cathode

For example

In a solution of Copper sulphate (CuSO₄), the Copper ions are positive (anions) and the sulphate ions are negative (cations)

When we pass a current through the electrodes: The cations (-ve) are attracted to the anode (+ve)

The anions (+ve) are attracted to the cathode (-ve)

As the copper ions are positively charged (anions) they will be attracted to the cathode (negative) and you should see a film of copper metal start to be deposited on the cathode

We can use this to coat objects in metal and is called - electroplating

Multiple Choice

what is the name of the solution that is being electrolysed?

• salt solution

• mineral solution

• electric solution

• electrolyte

Multiple Choice

Why does the electrolyte have to be a liquid?

• so the ions can move

• so it doesn't get too hot

• so the electrons can move

Copy and fill in the words

Electrolysis involves using e__________ to break down s_________ to form elements. Metals such as copper can be purified using electrolysis.

In order for the electric c______ to flow, the meatal must be in s_______ or molten so that the ions may move. Electricity is passed through solutions containing copper c_______, such as copper sulfate. The p_________ charge copper ions move towards the negative cathode.Pure copper forms on the c______.

word bank:

solution cathode electricity current positively substances compounds

Self assess!

Electrolysis involves using electricity to break down substances to form elements. Metals such as copper can be purified using electrolysis.

In order for the electric current to flow, the meatal must be in solution or molten so that the ions may move. Electricity is passed through solutions containing copper compounds such as copper sulphate. The positively charged copper ions move towards the negative cathode. Pure copper forms on the cathode.

word bank:

solution cathode electricity current positively substances compounds

Multiple Choice

The positive electrode is the?

• anode

• cathode

Multiple Choice

Negative ions are attracted to the?

• anode

• cathode

Multiple Choice

in oxidation, electrons are

• lost

• gained

Multiple Choice

The passage of electricity through a liquid in order to break it down is called...

• smelting

• electrolysis

Multiple Choice

During the electrolysis of coppe sulphate solution, copper is deposited ate the...

• anode

• cathode