Answer:
The molecular formula of the hydrocarbon compound is C₈H₁₈
Explanation:
The type of chemical substance in the question = Hydrocarbon
The mass of the hydrocarbon = 5.7 g
The mass of carbon in the given hydrocarbon (sample) = 4.8 g
The relative molecular mas of the hydrocarbon = 114 g
Therefore, the mass of hydrogen in the sample, H = 5.7 g - 4.8 g = 0.9 g
The ratio of the mass of carbon in the sample = 4.8/5.7
The ratio of the mass of hydrogen in the sample = 0.9/5.7
By the law of constant composition, we have;
The mass of carbon in a mole of the hydrocarbon = (4.8/5.7) × 114 g = 96 g
The molar mass of carbon, C = 12 g/mol
The number of moles of carbon in a mole of the hydrocarbon, 'n₁', is given as follows;
n₁ = 96 g/12 g = 8 moles
The mass of hydrogen in a mole of the hydrocarbon = (0.9/5.7) × 114 g = 18 g
The molar mass of hydrogen, H ≈ 1 g/mol
The number of moles of hydrogen in a mole of the hydrocarbon, 'n₂', is given as follows;
n₂ = 48 g/1 g = 18 moles
Therefore, in each each molecule of the compound, we have have 8 atoms of carbon, 'C', and 18 atoms of hydrogen, 'H'
Therefore, we get;
The molecular formula of the hydrocarbon compound is C₈H₁₈ which is the chemical formula for the hydrocarbon also known as octane
