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The following equipment was set up to measure the heat of combustion of an alkanol - HSC - SSCE Chemistry - Question 9 - 2017 - Paper 1
Question 9
The following equipment was set up to measure the heat of combustion of an alkanol. Thermometer Heat shield Tripod Loose fitting lid Conical flask containing wa... show full transcript
Worked Solution & Example Answer:The following equipment was set up to measure the heat of combustion of an alkanol - HSC - SSCE Chemistry - Question 9 - 2017 - Paper 1
Step 1
Which of the following equations could account for these observations?
Answer
The observations of black deposits in the conical flask and a measured heat of combustion lower than theoretical suggest incomplete combustion. Thus, the correct equation must produce solid carbon (C) as a byproduct due to insufficient oxygen.
Reviewing the options:
- Option A: This equation shows complete combustion with only carbon dioxide and water produced.
- Option B: Similarly, this one does not yield any solid carbon.
- Option C: This option produces hydrogen gas, which is not relevant for the observed phenomenon.
- Option D: This indicates incomplete combustion by producing both carbon dioxide and solid carbon, aligned with the observed black deposits.
Thus, the correct answer is D:
C2H6O(g) + 4 O2(g) → 2 CO2(g) + 2 C(s) + 6 H2O(g).