Earth's Resources OCR KS3 Y8

What is a salt in chemistry?

• A compound formed from an acid and a base

• A metal element

• A sugar solution

• A neutral gas

How is a salt made in the lab?

• By reacting an acid with a base

• By boiling water

• By filtering oil

• By mixing air and water

Which gas is released when a metal reacts with an acid?

• Hydrogen

• Oxygen

• Carbon dioxide

• Nitrogen

Which type of reaction forms a salt and water?

• Neutralisation

• Combustion

• Displacement

• Oxidation

Which of these is a base?

• Copper oxide

• Hydrochloric acid

• Sodium chloride

• Carbon dioxide

Which metal can be extracted using carbon?

• Iron

• Sodium

• Potassium

• Calcium

Why can't carbon be used to extract aluminium?

• Aluminium is more reactive than carbon

• Carbon is too expensive

• Aluminium is unreactive

• Carbon reacts with the air

What is reduction?

• The removal of oxygen from a substance

• The gain of oxygen

• The release of energy

• The cooling of a substance

What is oxidation?

• The gain of oxygen by a substance

• The loss of oxygen

• The addition of hydrogen

• The release of heat

Which word equation represents the reduction of iron oxide?

• Iron oxide + carbon → iron + carbon dioxide

• Iron + carbon → iron oxide + carbon dioxide

• Iron oxide + hydrogen → iron + oxygen

• Iron + oxygen → iron oxide