What is the mass, in mg, of carbon formed when 3.0 × 10⁻³ mol of propene undergoes incomplete combustion?
$$2C_3H_6 + 3O_2 \rightarrow 6C + 6H_2O$$ - AQA - A-Level Chemistry - Question 11 - 2017 - Paper 3
Question 11
What is the mass, in mg, of carbon formed when 3.0 × 10⁻³ mol of propene undergoes incomplete combustion?
$$2C_3H_6 + 3O_2 \rightarrow 6C + 6H_2O$$
Worked Solution & Example Answer:What is the mass, in mg, of carbon formed when 3.0 × 10⁻³ mol of propene undergoes incomplete combustion?
$$2C_3H_6 + 3O_2 \rightarrow 6C + 6H_2O$$ - AQA - A-Level Chemistry - Question 11 - 2017 - Paper 3
Step 1
Calculate moles of carbon formed
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Answer
According to the balanced equation, 2 moles of propene produce 6 moles of carbon. Therefore, the moles of carbon produced from 3.0 × 10⁻³ mol of propene can be calculated as:
Moles of carbon=3.0×10−3 mol C3H6×2 mol C3H66 mol C=9.0×10−3 mol C
Step 2
Convert moles of carbon to mass
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Answer
To find the mass of carbon, use the molar mass of carbon (C), which is approximately 12 g/mol:
Mass (g)=Moles×Molar Mass=9.0×10−3 mol×12 g/mol=0.108 g
Step 3
Convert mass to milligrams
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Answer
Convert grams to milligrams by multiplying by 1000:
0.108 g×1000=108 mg
Step 4
Final answer
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Answer
The mass of carbon formed is therefore 1.08 × 10² mg.
