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Question
The equation for the burning of octane is:
\[\ce{2C8H18 + 25O2 -> 16CO2 + 18H2O}\]
- How many moles of carbon dioxide are produced when one mole of octane burns?
- What volume, at STP, is occupied by the number of moles determined in (a)?
- If the relative molecular mass of carbon dioxide is 44, what is the mass of carbon dioxide produced by burning moles of octane?
- What is the empirical formula of octane?
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Solution
a. 2 moles of C8H18 produces = 16 moles of CO2
∴ 1 mole of C8H18 will produce = `16/2`
= 8 moles of CO2
b. 1 mole of CO2 occupies = 22.4 L at STP.
∴ 8 moles of CO2 will occupy = 22.4 × 8
= 179.2 L at STP
c. 1 mole of carbon dioxide has molecular mass = 44
16 moles of carbon dioxide has molecular mass = 44 × 16
= 704 g
d. Empirical formula of octane is C4H9.
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