Question

Calculate the molecular masses of the following compounds:
(a) Methanol, $C{H_3}OH$
(b) Ethanol, ${C_2}{H_5}OH$

Answer 1

Molecular mass of a compound is defined as the sum total of masses of elements present in that compound. It is calculated by multiplying the atomic mass of an element with the total no of atoms of that element in that compound.

Complete step by step answer:
Molecular mass is often expressed in the unit $amu$.
Methanol is the simplest alcohol, which is an organic compound consisting of a hydroxyl group and a methyl group. It is colorless and has a sweet odor. It is a volatile substance and very inflammable. It is also a very toxic substance as its raw consumption can lead to blindness.
It is mainly used in the manufacturing of acetic acid and formaldehyde. It was first isolated in the year $1661$. It is also used in the production of other hydrocarbons. It is a very good energy carrier and used as fuel for combustion engines. It is also a precursor for producing some methyl ethers and methylamines. Methanol has $1$ carbon and $1$ oxygen atoms and $4$ hydrogen atoms.
So its molecular mass will be:
=$(1 \times 12) + (1 \times 16) + (4 \times 1)$
=$12\, + \,16\, + \,4\, = \,32\,u$
Ethanol is the second alcohol in simple alcohol homologous series, it consists of one hydroxyl group and two methyl groups. It is in liquid state at room temperature. it also has its peculiar smell. It is the compound which is present in all alcoholic drinks as the active compound. Its different concentrations describe different alcoholic drinks.
It has $2$ carbon atoms, $1$ oxygen atom, and $6$ hydrogen atoms.
So its molecular mass will be:
=$(2 \times 12) + (1 \times 16) + (6 \times 1)$
=$(24) + (16) + (6)\, = \,46\,u$

Note:
Ethanol is very soluble in water and also used in various fields and industries. It is also present in medicines such as cough syrups that’s why some cough syrups have drowsy effects. Its raw consumption is also very hazardous for health.