Answer:
Empirical formula: CH
Molecular formula: C₆H₆
Explanation:
Based on the combustion of a hydrocarbon, the moles of CO₂ = Moles of Carbon in the hydrocarbon and the moles of H₂O = 1/2 moles of hydrogen in the hydrocarbon.
The empirical formula is the simplest whole number of atoms present in a molecule. With the moles of C and H we can find empirical formula:
<em>Moles C -Molar mass CO₂ = 44.01g/mol-:</em>
13.82g * (1mol / 44.01g) = 0.314 moles C
<em>Moles H -Molar mass H₂O = 18.01g/mol-:</em>
2.829g H₂O * (1mol / 18.01g) = 0.157 moles H₂O * (2mol H / 1mol H₂O) = 0.314 moles of H
The ratio of moles H: moles C:
0.314 moles / 0.314 moles = 1
That means empirical formula is:
<h3>CH</h3><h3 />
With the molecular weight and empirical formula we can find the molecular formula:
Molar mass CH = 12.01g/mol+1.01g/mol = 13.02g/mol
As the molecular weight of the molecule is 78.11amu = 78.11g/mol, there are:
78.11g/mol / 13.02g/mol = 6 times the empirical formula in the molecular formula
That means molecular formula is:
<h3>C₆H₆</h3>
