Balance the equation for the combustion of propane - AQA - GCSE Chemistry Combined Science - Question 1 - 2020 - Paper 2
Question 1
Balance the equation for the combustion of propane.
C₃H₈ + O₂ → 3 CO₂ + 4 H₂O
Worked Solution & Example Answer:Balance the equation for the combustion of propane - AQA - GCSE Chemistry Combined Science - Question 1 - 2020 - Paper 2
Step 1
Balance the equation for the combustion of propane.
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Answer
To balance the combustion equation of propane (C₃H₈), we write:
C3H8+5O2→3CO2+4H2O
In this equation, we have balanced the number of carbon, hydrogen, and oxygen atoms on both sides.
Step 2
Describe the test for carbon dioxide.
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Answer
The test for carbon dioxide involves passing the gas through lime water (calcium hydroxide solution). When carbon dioxide is present, it reacts with lime water to form calcium carbonate, which turns the solution milky or cloudy.
Result: The lime water turns milky, indicating the presence of carbon dioxide.
Step 3
Complete the symbol equation for the reaction.
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Answer
The symbol equation for the cracking of propane to produce propene and hydrogen is:
C3H8→C3H6+H2
Step 4
Describe the test for hydrogen.
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Answer
To test for hydrogen gas, you can use a lit splint. When hydrogen is present, it will burn with a distinctive squeaky pop sound.
Result: A pop sound is heard when the splint is introduced to hydrogen.
Step 5
Describe the test for alkenes.
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Answer
The test for alkenes involves adding bromine water (which is brown in color) to the alkene. If alkene is present, the brown color of bromine water will decolorize.
Colour change: The bromine water changes from brown to colorless.
