Combustion & Pollutants in the Atmosphere

Question 1

When hydrogen atoms are present in a fuel, they are ___________ to water.

Water is not a _____________.

Answer 1

oxidised

pollutant

Question 2

When there are lots of oxygen atoms present during combustion, the carbon atoms are _____________________ to ________________.

When there are fewer oxygen atoms present, ______________________ or _________ may be produced during combustion.

Answer 2

completely oxidised
carbon dioxide

carbon monoxide
carbon

Question 3

Complete combustion of a hydrocarbon fuel occurs when there is a _________________________.

Answer 3

good supply of oxygen

Question 4

What does complete combustion release and produce?

Answer 4

It releases the maximum amount of energy and produces carbon dioxide and water.

Question 5

Give an example of a complete combustion equation using methane:

Answer 5

methane + oxygen → carbon dioxide + water

Question 6

Incomplete combustion of a hydrocarbon fuel occurs when there is a ________________________.

Answer 6

poor supply of oxygen

Question 7

In incomplete combustion, ___________ is released.

__________ is still produced from the hydrogen atoms.

Instead of _________________, you might get carbon monoxide or ___________________.

Answer 7

less energy

Water

carbon monoxide
particulate carbon

Question 8

Give an example of an incomplete combustion equation using ethane:

Answer 8

ethane + oxygen → carbon monoxide + water

Question 9

What is the formula for carbon monoxide?

Answer 9

CO

Question 10

What is the formula for a carbon particulate?

Answer 10

C

Question 11

What is another term for particulate carbon?

Answer 11

Soot.

Question 12

Why does soot form? (2 marks).

Answer 12

Incomplete combustion of a fuel because there is insufficient oxygen.

Question 13

Why is carbon monoxide dangerous to humans?

Carbon monoxide is a __________________ which ______________________ in your ___________________, preventing them from ___________________________ in your body.

Carbon monoxide is _____________________________, so it is very difficult to tell if you are breathing it in.

Answer 13

poisonous gas
binds to haemoglobin
red blood cells
carrying oxygen to cells

colourless and odourless

Question 14

What can be installed to detect carbon dioxide?

Answer 14

Electronic detectors which are installed near boilers.

Question 15

What are 3 reasons why particulate carbon (soot) cause health problems for humans:
1.
2.
3.

Answer 15

1. Because it irritates the lining of the lungs
2. Can make asthma worse
3. Can cause cancer.

Question 16

Particulate carbon can cause global dimming, which may __________________.

Answer 16

reduce rainfall

Question 17

What is global dimming?

The gradual reduction in ____________________ from the Sun to ____________________ because of ___________________ in the atmosphere produced by _____________________.

Answer 17

radiation energy
Earth’s surface
small particles
human activities

Question 18

Where does the pollutant: carbon dioxide come from?

Answer 18

Complete combustion of any fuel containing carbon atoms.

Question 19

Where do the pollutants: carbon monoxide and carbon particulates come from?

Answer 19

Incomplete combustion of any fuel containing carbon atoms.

Question 20

Where does the pollutant: Unburned Hydrocarbons come from?

Answer 20

Hydrocarbon fuel molecules that have not been oxidised at all.

Question 21

Where does the pollutant: Sulfur dioxide, SO2 come from?

Answer 21

Combustion of a fossil fuel which contains sulfur impurities.

Question 22

Where does the pollutant: Nitrogen oxides, NOx come from?

Answer 22

Oxidation of atmospheric nitrogen inside the engine of a vehicle.

Question 23

What is the equation for the oxidation of sulfur?

Answer 23

sulfur + oxygen → sulfur dioxide

Question 24

Sulfur dioxide is then ________________ in the atmosphere to _________________, ______.

This gas dissolves in rainwater to make acid rain: _________.

Answer 24

further oxidised
sulfur trioxide
SO3

H2SO4

Question 25

Sulfur dioxide is then ________________ in the atmosphere to _________________, ______. This gas dissolves in rainwater to make acid rain: _________.

Answer 25

further oxidised sulfur trioxide SO3 H2SO4

Question 26

Nitrogen is ____________ in fuels, but the ______________________________ inside a car engine can cause the nitrogen and oxygen in the air to react together to make _____________________.

Answer 26

not present high temperature and pressure oxides of nitrogen

Question 27

What are the two oxides of nitrogen made inside engines?

Answer 27

NO NO2

Question 28

What are the two environmental effects of oxides of nitrogen?

Answer 28

Acid rain. Photochemical smog (when reacting with other pollutants).

Question 29

Explain how reducing the amount of sulfur in fossil fuels reduces the erosion of limestone: (4 marks) Less sulfur reacts with oxygen to form ________________. So less ______________________. So less ____________. So less limestone ______________________.

Answer 29

sulfur dioxide sulfur dioxide emitted acid rain reacts with acid rain