Answer:
The molecular formula is C6H14
Explanation:
Step 1: Data given
Suppose the mass of compound = 100 grams
A compound contains:
Carbon = 83.65 % = 83.65 grams
Hydrogen = 16.35 % = 16.35 grams
Atomic mass of carbon = 12.01 g/mol
Atomic mass of hydrogen = 1.01 g/mol
Molar mass of compound = 86.2 g/mol
Step 2: Calculate moles
Moles = mass / molar mass
Moles carbon = 83.65 grams / 12.01 g/mol
Moles carbon = 6.965 moles
Moles hydrogen = 16.35 grams / 1.01 g/mol
Moles hydrogen = 16.19 moles
Step 3: Calculate mol ratio
We divide by the smallest amount of moles
C: 6.965 moles / 6.965 moles = 1
H = 16.19 moles / 6.965 moles = 2.33
This means for 1 mol C we have 2.33 moles H OR for 3 moles C we have 7 moles H
The empirical formula is C3H7
The molecular mass of this formula is 43.1 g/mol
Step 4: Calculate molecular formula
We have to multiply the empirical formula by n
n = 86.2 g/mol / 43.1 g/mol
n = 2
Molecular formula = 2*(C3H7) = C6H14
The molecular formula is C6H14
