Answer: The empirical formula for the given compound is [tex]C_8H_{15}O_2[/tex]
Explanation:
We are given:
Percentage of C = 67.09 %
Percentage of H = 10.56 %
Percentage of O = 22.35 %
Let the mass of compound be 100 g. So, percentages given are taken as mass.
Mass of C = 67.09 g
Mass of H = 10.56 g
Mass of O = 22.35 g
To formulate the empirical formula, we need to follow some steps:
Moles of Carbon =[tex]\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{67.09g}{12g/mole}=5.59moles[/tex]
Moles of Hydrogen = [tex]\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{10.56g}{1g/mole}=10.56moles[/tex]
Moles of Oxygen = [tex]\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{22.35g}{16g/mole}=1.40moles[/tex]
For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 1.40 moles.
For Carbon = [tex]\frac{5.59}{1.40}=3.99\approx 4[/tex]
For Hydrogen = [tex]\frac{10.56}{1.40}=7.5[/tex]
For Oxygen = [tex]\frac{1.40}{1.40}=1[/tex]
Multiplying the mole ratio by '2' to make the mole ratios a whole number
Mole ratio of Carbon = (4 × 2) = 8
Mole ratio of Hydrogen= (7.5 × 2) = 15
Mole ratio of Oxygen = (1 × 2) = 2
The ratio of C : H : O = 8 : 15 : 2
In the compound, there are 8 atoms of carbon, 15 atoms of hydrogen and 2 atoms of oxygen
Hence, the empirical formula for the given compound is [tex]C_8H_{15}O_2[/tex]