A. C2H6O
B. C6H18O3
C. C6H12O6
D. C2H5O
¨ The empirical formula of a compound gives the simplest whole-number ratio of the atoms present in the compound. To determine the molecular formula of the compound, we need to know the molar mass of the compound.
¨ The molar mass of the empirical formula C2H6O is:
¨ (2 × 12.01 g/mol) + (6 × 1.01 g/mol) + (1 × 16.00 g/mol) = 46.08 g/mol
¨ The given molar mass of the compound is 138 g/mol, which is exactly three times the molar mass of the empirical formula. This means that the molecular formula of the compound must be three times the empirical formula.
¨ The molecular formula of the compound can be found by multiplying the subscripts in the empirical formula by 3:
¨ C2H6O × 3 = C6H18O3
¨ Therefore, the molecular formula of the compound is (B) C6H18O3.
Submitted by :- Jamil Ahmed