C1b - Using carbon fuels

Question 1

Suggest the key factors that need to be considered when choosing a fuel for a particular purpose(7)

Answer 1

toxicity

energy value

availability

cost

(ease of) use

pollution (e.g. acid rain, greenhouse effect)

storage

Question 2

Why is the amount of fossil fuels being burnt increasing? (2)

Answer 2

increasing world population

growth of use in developing countries(China, India)

Question 3

Describe an experiment to show that combustion of a hydrocarbon in a plentiful supply of air produces carbon dioxide and water and heat energy(4)

Answer 3

1. products of combustion drawn into apparatus using water pump
2. pass into boiling tube with blue cobalt chloride paper –> pink => water
3. pass into boiling tube with limewater –> cloudy => carbon dioxide
4. apparatus becomes hot => shows heat energy is released during combustion

Question 4

Word equation for complete combustion

Answer 4

hydrocarbon + oxygen –> carbon dioxide + water

Question 5

Word and balanced symbol equation for the complete combustion of propane(2)

Answer 5

propane + oxygen → carbon dioxide + water

C3H8 + 5O2 → 3CO2 + 4H2O

Question 6

Explain the advantages of complete combustion over incomplete combustion of hydrocarbon fuels(3)

Answer 6

less dirty soot produced, which can cause breathing problems

more (heat) energy released

no poisonous carbon monoxide produced, which is poisonous as it prevents haemoglobin in red blood cells from binding with oxygen

Question 7

Word equation for incomplete combustion

Answer 7

hydrocarbon + oxygen –> carbon + carbon monoxide + water

Question 8

Word and balanced symbol equation for the incomplete combustion of ethane(3)

Answer 8

Ethane + Oxygen —> carbon monoxide + water + carbon

C2H6 + 202 –> CO + 3H20 + C