Reactions

Question 1

What is air made up of

Answer 1

Oxygen 21%
Nitrogen. 78%
Argon. 0.9%
Carbon dioxide 0.032%

Question 2

3 physical properties of oxygen

Answer 2

Colourless
Odourless
Gas
(Not very soluble in water, some density as air)

Question 3

What is the word equation for respiration

Answer 3

Sugar+ oxygen+ carbon dioxide+ water (+energy)

Question 4

What is the test for oxygen

Answer 4

Relights a glowing splint

Question 5

What chemicals do you need to test for oxygen

Answer 5

Hydrogen peroxide
Catalyst manganese dioxide

Question 6

What is a catalyst

Answer 6

A chemical that speeds up chemical reactions without being used up itself

Question 7

What are some examples of industrial catalysts

Answer 7

Iron
Plantium
Vanadium oxide

Question 8

What is the equation when testing for oxygen

Answer 8

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

Question 9

What is the test for hydrogen

Answer 9

With a lighted splint and you will hear a squeaky pop

Question 10

What chemicals do you need when testing for hydrogen

Answer 10

Hydrochloric acid
Magnesium

Question 11

What is the equation when testing for hydrogen

Answer 11

Magnesium + hydrochloric acid ——————> magnesium chloride + hydrogen

Question 12

What is the test for carbon dioxide

Answer 12

After you bubble gas into limewater, the limewater turns from colourless to milky white

Question 13

What is the equation for testing for carbon dioxide

Answer 13

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

Question 14

What chemicals do you need when testing for carbon dioxide

Answer 14

Hydrochloric acid
Marble chips ( calcium carbonate)

Question 15

What are 3 uses of carbon dioxide

Answer 15

Fizzy drinks
Fire extinguisher
Dry ice

Question 16

2 physical properties of carbon dioxide

Answer 16

Gas
Colourless
Odourless

Question 17

2 observations when calcium carbonate is added to hydrochloric acid

Answer 17

Fizzing/bubbles of gas
Calcium carbonate disappears

Question 18

List 3 uses of oxygen

Answer 18

Welding torches.
Rocket fuel.
Breathing apparatus in hospitals.

Question 19

Name the 2 products of the reaction when candle wax combusts

Answer 19

Carbon dioxide and water

Question 20

What does exothermic mean?

Answer 20

A reaction that gives out heat
(Temp drops)

Question 21

Why does endothermic mean

Answer 21

A reaction that takes in heat

Question 22

What happens when zinc is added to copper?

Answer 22

The blue copper sulphate solution turns to a colourless liquid .
The zinc powder turns to brown sludge.
This is exothermic as the temp increases during the reaction

Question 23

What are 3 pieces of evidence to tell us that a chemical reaction is taking place?
When zinc is added to copper

Answer 23

Rise in temperature.
Powder disappears.
Liquid changes from blue to colourless

Question 24

What is oxidation

Answer 24

An oxidation reaction occurs when a chemical reacts with oxygen. (The adding of oxygen)

Question 25

What is reduction

Answer 25

The opposite of oxidation and occurs when a substance loses oxygen. (Removal of oxygen)

Question 26

What is a redox reaction?

Answer 26

A reaction where REDuction and OXidation takes place together. (Oxidation and reduction both taking place)

Question 27

Decide what part has been oxidised and reduction Calcium+magnesium oxide— calcium oxide+ magnesium

Answer 27

Magnesium oxide was reduced to magnesium. Calcium was oxidised to calcium oxide

Question 28

Decide what part has been oxidised and reduction Zinc oxide+ hydrogen— zinc + water

Answer 28

Zinc oxide was reduced to zinc. Hydrogen was oxidised to water.

Question 29

Decide what part has been oxidised and reduction Aluminium oxide + potassium— aluminium + potassium oxide

Answer 29

Aluminium oxide was reduced to aluminium. Potassium was oxidised to potassium oxide.

Question 30

Decide what part has been oxidised and reduction Aluminium + iron oxide— iron+ aluminium oxide

Answer 30

Iron oxide was reduced to iron. Aluminium was oxidised to aluminium oxide.

Question 31

Decide what part has been oxidised and reduction Copper oxide+ carbon— copper + carbon dioxide

Answer 31

Copper oxide reduced to copper. Carbon oxidised to carbon dioxide.

Question 32

Tell me about a thermite reaction.

Answer 32

In the Thermite reaction, the two reactants are iron oxide and Aluminium. The Thermite reaction is a very exothermic reaction as it gives out lots of heat. The reactant iron oxide is reduced to molten iron. This reaction was used to weld train tracks together.