Reactions

Question 0

What percentage of the air is nitrogen?

Answer 0

78%

Question 1

What percentage of oxygen is in the air?

Answer 1

21%

Question 2

What percentage of the air is Argon?

Answer 2

0.9%

Question 3

In the air how much carbon dioxide is there?

Answer 3

0.037%

Question 4

Three physical features of Oxygen are?

Answer 4

Gas, colourless, odourless

Question 5

Three uses of oxygen are?

Answer 5

Welding torches, rocket fuel, breathing apparatus in hospitals

Question 6

The word equation for respiration is?

Answer 6

Sugar+oxygen->Carbon dioxide+water(+energy)

Question 7

Candle wax is made up of substances containing carbon and hydrogen. What are the two products of the reaction.

Answer 7

Carbon dioxide+water

Question 8

Describe the chemical test for water.

Answer 8

Use the chemical anhydrous copper sulphate which changes colour from white to blue in presence of water

Question 9

What’s the word equation for Oxygen?

Answer 9

Manganese dioxide

Hydrogen peroxide———————->water+oxygen

Question 10

What are the chemicals required for the test for oxygen?

Answer 10

Hydrogen peroxide and catalyst+manganese dioxide

Question 11

The test for oxygen?

Answer 11

Relights a glowing splint

Question 12

What is a catalyst, and what does it do?

Answer 12

A chemical that speeds up the chemical reaction without being used up

Question 13

Examples of industrial catalyst.

Answer 13

Iron, platinum and vanadium (V) oxide

Question 14

What is an enzyme, and what does it do?

Answer 14

Is a soluble protein molecules that speed up chemical reactions in cells

Question 15

Name some of the chemical reactions that enzymes are involved in.

Answer 15

DNA replication, protein synthesis, and digestion

Question 16

What is the word equation for the hydrogen test?

Answer 16

Magnesium+hydrochloric acid->magnesium chloride+hydrogen

Question 17

The chemicals required for the test for hydrogen are.

Answer 17

Hydrochloric acid and magnesium

Question 18

The test for hydrogen.

Answer 18

Using a lighted splint, you will hear a squeaky pop

Question 19

The word equation for the test of carbon dioxide is.

Answer 19

Calcium carbonate+hydrochloric acid->calcium chloride+water+carbon dioxide

Question 20

The chemicals required for the test for carbon dioxide are.

Answer 20

Hydrochloric acid and calcium carbonate

Question 21

The test for carbon dioxide.

Answer 21

When carbon dioxide is bubbled through limewater, it turns milky

Question 22

Three uses for carbon dioxide is.

Answer 22

Fizzy drinks, fire extinguisher, dry ice

Question 23

Observations when calcium carbonate is added to hydrochloric acid are.

Answer 23

Metal carbonate disappears to give a clear solution, Limewater turns milky

Question 24

Physical properties of carbon dioxide are.

Answer 24

colourless and odourless

Question 25

What is an exothermic reaction?

Answer 25

They give out heat

Question 26

What is an endothermic reaction?

Answer 26

They take in heat

Question 27

What is oxidation?

Answer 27

An oxidation reaction occurs when a chemical reacts with oxygen.

Question 28

What is reduction?

Answer 28

Reduction is the opposite of oxidation and occurs when a substance loses oxygen.

Question 29

What is a redox reaction?

Answer 29

A substance which reduces another substance.