Question

Write the molecular formula of ethanol.

Answer 1

Hint: Ethanol is the most common alcohol in organic chemistry. It is primarily used as a solvent. To carry out the molecular formula of ethanol, use the basic nomenclature rules of IUPAC.

Complete Solution :
- A molecular formula is the short representation of the structural framework of the constituents of any chemical compound.
- In order to determine the molecular formula, we will go through some basic e rules of IUPAC nomenclature.
- According to IUPAC, the prefix of the given compound is ‘eth’ which represents the name of any compound consisting of two carbon atoms in the main parent chain. In other words, ethanol has two carbon atoms.
- From the suffix, it is quite evident that the main functional group present here is alcohol because the suffix used here is ‘-ol’. This shows that there is a replacement of one hydrogen atom with hydroxyl group (OH).
- Since carbon is a tetravalent atom, it should fulfil the remaining valency with hydrogen atom. Thus, a two-carbon atom parent chain should have 6 hydrogen atoms.
- Hence, the molecular formula of ethanol is ${{C}_{2}}{{H}_{6}}O$ or ${{C}_{2}}{{H}_{5}}OH$

Additional information: Ethanol is liquid at room temperature. It produces carbon dioxide, water vapour, heat and light when it is burnt in the presence of oxygen.

Note: Ethanol is a volatile flammable and colourless liquid. It can be obtained from fermentation of sugar or plant materials. It is the intoxicating ingredient of alcoholic beverages. It is also used as a solvent and in explosives.