Chemistry Topic 2 Redox, rusting and iron

What is oxidation?

The gain of hydrogen or the loss of hydrogen/electrons

What is reduction?

The gain of hydrogen/electrons or the loss of oxygen

What is the reaction between magnesium and oxygen?

Bright white light

white solid forms

heat released

2Mg + O2 → 2MgO

What is the reaction between sulfur and oxygen?

Yellow solid melts to a red liquid

Burns with blue flame

Releases heat and pungent colourless gas (sulfur dioxide)

S + O2 → SO2

What is the reaction between carbon and oxygen?

Black carbon burns in a plentiful supply of oxygen

Colourless gas forms

C + O2 → CO2

What is the reaction between copper oxide and hydrogen?

Goes from a black solid to pink-brown solid

CuO + H2 → Cu + H2O

What is a redox reaction?

A reaction in which both oxidation and reduction happen at the same time

What are the conditions in which rust occurs?

Water and oxygen

It is an oxidation reaction, it forms hydrated iron (lll) oxide which is a red-brown flaky solid

What are the methods of preventing rust?

Painting

Oiling

Plastic coating

Metal covering/plating

Sacrificial protection

Galvanising

What are the raw materials in the blast furnace?

coke/carbon, limestone

How does the reducing agent form?

Hot air converts carbon into carbon dioxide and then carbon monoxide- exothermic reaction

C + O2 → CO2

CO2 + C → 2CO

How is the iron oxide reduced?

Carbon monoxide reduces iron oxide to iron

Fe3O2 + 3CO → 3Fe + 3CO2

How are the acidic impurities removed?

Limestone undergoes thermal decomposition and the calcium oxide produced reacts with the acidic impurities to produce molten slag- this gets tapped off at the base

CaCO3 → CaO + CO2

CaO + SiO2 → CaSiO3