Answer:
C₃H₄O₃
Explanation:
The empirical formula is the simplest whole-number ratio of atoms present in a molecule. To solve this question we must find the moles of CO2 = Moles of Carbon and moles of H2O = 1/2 moles H.
With the difference in masses of the atoms we can find the mass of ascorbic acid and its moles as follows:
<em>Moles CO2 = Moles C -Molar mass: 44.01g/mol-</em>
4.31g CO2 * (1mol / 44.01g) = 0.0979 moles C * (12.01g/mol) = 1.18g C
<em>Moles H2O -Molar mass: 18.01g/mol</em>
1.17g H2O * (1mol / 18.01g) = 0.0650 moles H2O * (2mol H / 1mol H2O) = 0.130 moles H = 0.13g H
<em>Moles O:</em>
Mass O: 2.87g-0.13g H - 1.18g C = 1.56g O
<em>Moles O:</em>
1.56g O * (1mol/16g) = 0.0975 moles O
Dividing each number of moles of atoms in the moles of Oxygen (The lower number of moles:
O/O = 0.0975 moles O/0.0975 moles O = 1
H/O = 0.130 moles H/ 0.0975 moles O = 1.333
C/O = 0.0979 moles C/ 0.0975 moles O = 1
As empirical formula requires whole-numbers we need to multiply this ratio 3 times:
O = 1*3 = 3
H = 1.333*3 = 4
C = 1*3 = 3
Empirical formula of ascorbic acid is:
<h3>C₃H₄O₃</h3>
