Air

Question 1

Air is a mixture because

Answer 1

• composition varies from place to place

- different gases condense as liquids at different temperatures

Question 2

Cobalt chloride paper

Answer 2

Used to test for presence of water, blue when dry and pink when wet

Question 3

Limewater

Answer 3

Used to test for carbon dioxide (turns milky when present)

Question 4

Oxygen is prepared by the breakdown of

Answer 4

Hydrogen peroxide

Question 5

Manganese dioxide

Answer 5

Is a catalyst- it speeds up the breakdown of the hydrogen peroxide

Question 6

A glowing splint used to test

Answer 6

For oxygen (oxygen relights a glowing splint)

Question 7

Carbon dioxide is prepared by the reaction between

Answer 7

Dilute hydrochloric acid (HCI) and marble chips (calcium carbonate CaCO3)

Question 8

Oxygen is used for

Answer 8

Breathing welding and burning

Question 9

Carbon dioxide is used in

Answer 9

Photosynthesis fire extinguishers and fizzy drinks

Question 10

Air consists of the elements

Answer 10

78% nitrogen, 21% oxygen, 1% argon, (compounds) 0.03% carbon dioxide, water vapour 0-4%