Chemical Changes - Oxidation and reduction

What is oxidation in terms of electrons?

Oxidation is the loss of electrons

What is oxidation?

Oxidation is the gain of oxygen

What is reduction?

Reduction is the loss of oxygen

What is reduction in terms of electrons?

Reducton is the gain of electrons

Why can carbon be used to extract copper from copper oxide?

Carbon is more reactive than copper, so it can remove oxygen from copper oxide

Why can aluminium not be extracted from aluminium oxide using carbon?

Aluminium is more reactive than carbon, so carbon cannot remove oxygen from aluminium oxide, so electrolysis is therefore used.

If a substance loses electrons. What has happened to it?

It has been oxidised

If a substance gains electron. What has happened to it?

It has been reduced

What happens when a metal reacts with oxygen?

The metal reacts with oxygen to form metal oxide and the metal gains oxygen so it is oxidised but the metal also loses their electrons

How is carbon used to extract a metal from its oxide?

Carbon is more reactive than the metal and carbon removes the oxygen from the metal oxide so the metal oxide is reduced and carbon is oxidised

What is a redox reaction?

A redox reaction is a reaction in which oxidation and reduction both take place at the same time

Why is the reaction between magnesium and zinc ions a redox reaction?

Magnesium loses two electrons and is oxidised, zinc ions gain two electrons and are reduced, and oxidation and reduction occur at the same time, so it is a redox reaction

Zinc is added to copper sulfate. Why is it a redox reaction?

Zinc displaces copper because it is more reactive than copper and loses electrons and is oxidised. Copper ions gain electrons and are reduced. Oxidation and reduction occur at the same time, so it is a redox reaction

What happens to magnesium and oxygen electrons in magnesium oxide?

Magnesium loses two electrons, so it becomes oxidised and oxygen gains two electrons, so it is reduced

What is a displacement reaction?

When a more reactive metal displaces a less reactive metal from its compound

Why is copper not displaced from zinc sulfate by copper metal?

Copper is less reactive than zinc, so it cannot displace zinc from its compound

What happens when zinc is added to copper sulfate?

A reddish-brown copper forms, and the blue solution becomes paler