Using carbon fuels

Question 1

List the factors about fuels in order to choose the best

fuel for a particular purpose

Answer 1

- energy value
• availability
• storage
• cost
• toxicity
• pollution e.g. acid rain, greenhouse effect
• ease of use.

Question 2

Understand why complete combustion needs a

plentiful supply of oxygen

Answer 2

so water and carbon dioxide can be formed

Question 3

what does the complete combustion of a hydrocarbon

fuel only make?

Answer 3

only carbon dioxide and water

Question 4

Understand why incomplete combustion takes place

Answer 4

when there is not enough oxygen to burn the fuel completely

Question 5

Explain why a blue Bunsen flame releases more

energy than a yellow flame.

Answer 5

Blue is hotter bunsen flame and is complete combustion, but yellow bunsen flame is incomplete combustion.

Question 6

what does a yellow flame produce a lot of?

Answer 6

soot

Question 7

what does the incomplete combustion of a hydrocarbon

fuel make?

Answer 7

carbon monoxide, carbon (soot) and

water

Question 8

what is carbon monoxide?

Answer 8

a poisonous gas

Question 9

Explain why the amount of fossil fuels being burnt is

increasing:

Answer 9

• increasing world population
• growth of use in developing countries e.g. India
  and China.

Question 10

Evaluate the use (no recall expected) of different

fuels.

Answer 10

methane:
- non-toxic
- not easy to store
- burns to form carbon dioxide and water
butane:
- easier to store and transport than methane
- burns in the same way as methane
- used as a camping gas
coal:
- easy to store
- readily available
- pollution

Question 11

Construct the balanced symbol equation for the
incomplete combustion of a simple hydrocarbon fuel
given its molecular formula and the product (carbon
or carbon monoxide)

Answer 11

CH4 + O2 -> C + 2H2O

Question 12

Construct the balanced symbol equation for the
complete combustion of a simple hydrocarbon fuel
given its molecular formula.

Answer 12

CH4 + 2O2 -> CO2 + 2H2O

Question 13

Construct word equations to show the complete
combustion of a hydrocarbon fuel (not all reactants
and products given).

Answer 13

methane + oxygen -> carbon dioxide + water

Question 14

Construct word equations to show the incomplete
combustion of a hydrocarbon fuel (not all reactants
and products given)

Answer 14

methane + oxygen -> carbon monoxide + water

Question 15

Explain the advantages of complete combustion over

incomplete combustion of hydrocarbon fuels.

Answer 15

more energy is released throughout complete combustion