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Combustion of a 1.031-g sample of a compound containing only carbon, hydrogen, and oxygen produced 2.265 g of CO2(g) and 1.236 g of H2O
Question
Combustion of a 1.031-g sample of a compound containing only carbon, hydrogen,
and oxygen produced 2.265 g of CO2(g) and 1.236 g of H2O(g). What is the
empirical formula of the compound?
3 국
Molar masses in g/mol: CO2 = 44.01; H20 = 18.02; C = 12.01; H = 1.01
C3H50
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Chemistry
4 years
2021-08-05T20:16:49+00:00
2021-08-05T20:16:49+00:00 1 Answers
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Answers ( )
Answer:
C₃H₈O
Explanation:
From the question given above, the following data were obtained:
Mass of compound = 1.031 g
Mass of CO₂ = 2.265 g
Mass of H₂O = 1.236 g
Empirical formula =?
Next, we shall determine the mass of carbon, hydrogen and oxygen in the compound. This can be obtained as follow:
For carbon, C:
Mass of CO₂ = 2.265 g
Molar mass of CO₂ = 44.01 g/mol
Molar mass of C = 12.01 g/mol
Mass of C =?
Mass of C = molar mass of C / molar mass of CO₂ × mass of CO₂
Mass of C = 12.01/44.01 × 2.265
Mass of C = 0.618 g
For hydrogen, H:
Mass of H₂O = 1.236 g
Molar mass of H₂O = 18.02 g/mol
Molar mass of H₂ = 2 × 1.01 = 2.02 g/mol
Mass of H =?
Mass of H = Molar mass of H₂ / Molar mass of H₂O × Mass of H₂O
Mass of H = 2.02/18.02 × 1.236
Mass of H = 0.139 g
For oxygen, O:
Mass of compound = 1.031 g
Mass of C = 0.618 g
Mass of H = 0.139 g
Mass of O =?
Mass of O = Mass of compound – (mass of C + mass of H)
Mass of O = 1.031 – ( 0.618 + 0.139)
Mass of O = 1.031 – 0.757
Mass of O = 0.274 g
Finally, we shall determine the empirical formula. This can be obtained as follow:
C = 0.618 g
H = 0.139 g
O = 0.274 g
Divide by their molar mass
C = 0.618 / 12.01 = 0.051
H = 0.139 / 1.01 = 0.138
O = 0.274 / 16 = 0.017
Divide by the smallest
C = 0.051 / 0.017 = 3
H = 0.138 / 0.017 = 8
O = 0.017 / 0.017 = 1
Therefore, the empirical formula of the compound is C₃H₈O