When charcoal reacts in the presence of oxygen, carbon monoxide and carbon dioxide are produced according to the following chemical reactions - HSC - SSCE Chemistry - Question 20 - 2011 - Paper 1
Question 20
When charcoal reacts in the presence of oxygen, carbon monoxide and carbon dioxide are produced according to the following chemical reactions.
C(s) + \frac{1}{2} O_... show full transcript
Worked Solution & Example Answer:When charcoal reacts in the presence of oxygen, carbon monoxide and carbon dioxide are produced according to the following chemical reactions - HSC - SSCE Chemistry - Question 20 - 2011 - Paper 1
Step 1
Calculate moles of charcoal
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Answer
First, we need to determine the molar mass of charcoal (carbon, C). The molar mass of carbon is approximately 12 g/mol.
To find the moles of 400 g of charcoal:
moles of C=molar massmass=12 g/mol400 g≈33.33 mol
Step 2
Calculate gas produced from the first reaction
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In the first reaction, each mole of carbon produces 1 mole of carbon monoxide (CO).
Thus, using the moles of charcoal:
moles of CO=33.33 moles (from first reaction)
The molar mass of CO is approximately 28 g/mol.
Total mass of CO produced:
mass of CO=33.33 mol×28 g/mol=933.24extg
Step 3
Calculate gas produced from the second reaction
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In the second reaction, each mole of carbon produces 1 mole of carbon dioxide (CO₂).
Thus, using the moles of charcoal:
moles of CO₂=33.33 moles (from second reaction)
The molar mass of CO₂ is approximately 44 g/mol.
Total mass of CO₂ produced:
mass of CO₂=33.33 mol×44 g/mol=1466.52extg
Step 4
Calculate total mass of gas produced
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Now we can sum the masses of both gases produced:
Total gas mass = mass of CO + mass of CO₂
Total gas mass=933.24extg+1466.52extg=2399.76extg
Converting grams to kilograms:
Total gas mass = 2.4 kg
This closely matches the provided options and simplifies to 2.5 kg.
Step 5
Select the correct answer
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Answer
According to the calculations, the total mass of gas produced is approximately 2.5 kg.