Molecular formula of ethane

Ethane provides a simple example. After quantitative element analysis, the empirical formula for ethane is found to be CH3. A molecular mass of 30 is determined. The empirical formula weight of ethane, 15, is half of the molecular mass, 30. Therefore, the molecular formula of ethane must be 2(CH3)orC2He. 

The molecular formula of a compound is the actual number of atoms of each type present in a molecule. For example, the molecular formula of ethane is C2Hg, of ethanol is C2HgO and of ethanoic acid is C2H4O2. For many organic compounds the molecular formula and empirical formula are not the same. However, the molecular formula must be a whole number multiple of the empirical formula and therefore can be deduced if you know both the empirical formula and the relative molecular mass (M,) of the compound. 

The molecular formula shows the actual number of each of the different atoms present in a molecule. The molecular formula is more useful than the empirical formula. We use the molecular formula to write balanced equations and to calculate molar masses. The molecular formula is always a multiple of the empirical formula. For example, the molecular formula of ethane, is two times the... 

---

See also in sourсe #XX -- [ , , ]

---