Chemical reactions

Metal + Oxygen -->

• Metal hydroxide

• Metal oxide

• Metal chloride

• Salt

Calcium + Oxygen -->

• Calcium chloride

• Calcium hydroxide

• Calcium oxide

• Calcium oxide + hydrogen

Metal + Oxygen --> Metal oxide

This is a/an __________ reaction.

• rusting

• reduction

• oxidation

• displacement

Metal A is very reactive. It has to be kept under oil to prevent from reacting with air and water. What is A?

• Hydrogen

• Magnesium

• Zinc

• Lithium

The metals that do not reactive with oxygen.

• Gold & Zinc

• Zinc & Platinum

• Platinum & Gold

• Copper & Gold

What are the conditions needed for rusting to happen?

• water and acid

• Water and oxygen

• Oxygen and acid

• Carbon dioxide and oxygen

Which of the following is NOT a suitable method to prevent rusting of iron?

• Painting

• Galvanising

• Coat iron with oil

• Soak the iron in water

The diagram shows a set up of experiment. Does rusting happen? Why?

• Yes. Water and oxygen are present.

• Yes. Water is present.

• No. Water is present but oxygen is absent.

• No. Oxygen is present but water is present.

What is the function of anhydrous calcium chloride in the test tube?

• to absorb oxygen

• to absorb water vapour

• to absorb carbon dioxide

• to absorb air

Calcium is reacting with water to form bubbles of gas. What is the name of the gas?

• hydrogen

• oxygen

• carbon dioxide

• calcium hydroxide