Combustion

Question 1

combustion definition

Answer 1

when a hydrocarbon reacts with oxygen to produce new substances

Question 2

word equation for complete combustion

Answer 2

hydrocarbon (fuel) + oxygen — carbon dioxide + water (g)

Question 3

what are fossil fuels (definition)

Answer 3

naturally occurring hydrocarbon resources found in the Earth’s crust

Question 4

examples of fossil fuels?

Answer 4

coal, gas, oil

Question 5

name 4 smallest hydrocarbons

Answer 5

• methane
• ethane
• propane
• butane

Question 6

what is the chemical formula for methane

Answer 6

CH4

Question 7

what is the chemical formula for ethane

Answer 7

C2H6

Question 8

what is the chemical formula for propane

Answer 8

C3H8

Question 9

what is the chemical formula for butane

Answer 9

C4H10

Question 10

what is the greenhouse effect

Answer 10

there is too much carbon dioxide in the atmosphere surrounding the earth due to the burning of too many fossil fuels- this will entrap heat and light energy from the sun and overheat the planet

Question 11

what are the dangers of fossil fuels

Answer 11

fossil fuels can produce carbon dioxide through complete combustion and carbon monoxide and soot (pollution) through incomplete combustion

Question 12

what does the greenhouse effect lead to (6)

Answer 12

• – burning fossil fuels
• – greenhouse effect
• – heat is trapped in atmosphere
• – global warming
• – earth’s temperatures rise
• – ice caps melt
• – oceans rise and land floods
• – animals lose their habitats
• – extinction of species

Question 13

contrast complete and incomplete combustion

Answer 13

complete combustion happens when there is a sufficient amount of oxygen and incomplete combustion takes place when there is not enough oxygen

Question 14

chemical word equation for incomplete combustion

Answer 14

hydrocarbon + oxygen → carbon monoxide + carbon + water

Question 15

why is carbon monoxide damaging to health

Answer 15

it is colourless, tasteless and has no smell which makes it hard to detect when it latches onto haemoglobin and takes up space in the red blood cell, leaving little to none for oxygen. Because of this, it becomes hard to breathe, but the brain and/ or heart are also affected by the chemical as well.

Question 16

what are some risks/ hazards of using a bunsen burner

Answer 16

you could burn yourself on the flame/ chimney

Question 17

what parts are ok to touch when the bunsen burner is on

Answer 17

rubber tubing, base, collar

Question 18

list the parts of a bunsen burner

Answer 18

flame, chimney, collar, air hole, base, rubber tubing

Question 19

air hole position for a safety flame

Answer 19

fully closed

Question 20

colour of safety flame

Answer 20

yellow

Question 21

use of safety flame

Answer 21

easily visible for when the bunsen burner is on but not heating a substance

Question 22

name of flame when the air hole is half-open

Answer 22

blue

Question 23

colour of flame when the air hole is half-open

Answer 23

blue

Question 24

use of blue flame

Answer 24

gently heat a substance

Question 25

air hole position for roaring blue flame

Answer 25

fully open

Question 26

colour of flame when air hole is fully open

Answer 26

blue

Question 27

use of roaring blue flame

Answer 27

the hottest of the three flames to rapidly heat or sterilise a substance

Question 28

what is thermal decomposition

Answer 28

when a compound breaks down as a result of heating and forms two different new substances from this one reactant

Question 29

what is produced when calcium carbonate is heated

Answer 29

copper carbonate → copper oxide + carbon dioxide | CuCO3 → CuO + CO2

Question 30

what is the colour of calcium carbonate

Answer 30

green

Question 31

what is the colour of calcium oxide

Answer 31

black

Question 32

what colour changes can we see when calcium carbonate is being heated

Answer 32

colour changes from green to black during reaction

Question 33

how do we know of carbon dioxide has been produced by this reaction as well

Answer 33

use lime-water and see if it turns a cloudy/ milky white

Question 34

why must thermal energy be supplied constantly for the reaction to keep happening

Answer 34

because thermal decomposition is an endothermic reaction

Question 35

what is an endothermic reaction

Answer 35

when a reaction gains energy from its surroundings

Question 36

what is an exothermic reaction

Answer 36

when a reaction GIVES OUT energy to the surroundings

Question 37

what equipment do we use to test the thermal decomposition of calcium carbonate

Answer 37

- calcium carbonate in a test tube - test tube rack - bunsen burner - gas tap