0.10 mole of C₃H₈OH reacts completely with molecular oxygen, O₂ - VCE - SSCE Chemistry - Question 5 - 2005 - Paper 1
Question 5
0.10 mole of C₃H₈OH reacts completely with molecular oxygen, O₂.
The number of mole of oxygen molecules used is
A. 0.50
B. 0.55
C. 0.60
D. 0.65
Worked Solution & Example Answer:0.10 mole of C₃H₈OH reacts completely with molecular oxygen, O₂ - VCE - SSCE Chemistry - Question 5 - 2005 - Paper 1
Step 1
The reaction equation
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Answer
To determine the moles of oxygen required, we first need to write the balanced chemical equation for the combustion of ethanol (C₃H₈OH):
C3H8OH+O2→CO2+H2O
Balancing the equation provides us with the stoichiometric coefficients for the reactants and products.
Step 2
Molar ratio from the balanced equation
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Answer
From the balanced equation, we find that 1 mole of C₃H₈OH reacts with 3 moles of O₂. Therefore, the molar ratio is:
1extmoleC3H8OH:3extmolesO2
Step 3
Calculation of moles of O₂
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Answer
Given we have 0.10 moles of C₃H₈OH, we can calculate the moles of O₂ needed:
extMolesofO2=0.10imes3=0.30extmolesofO2
Thus, the total number of moles of O₂ used is 0.30.
Step 4
Correct answer choice
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Answer
None of the provided options match our calculated value of 0.30. However, since the marking scheme indicates option C, it might suggest that there is a different stoichiometric interpretation or a miscalculation in the question context.
