Question

The empirical formula of a compound is $C{H_2}{O_2}$. What could be its molecular formula?
A.${C_2}{H_2}{O_2}$
B.${C_2}{H_2}{O_4}$
C.${C_2}{H_4}{O_4}$
D.$C{H_4}{O_4}$

Answer 1

Empirical formula: It is defined as the chemical formula which shows the simplest ratio of elements in the compound.
Molecular formula: It is a chemical formula which shows the actual ratio of the elements in the compound.

Complete step by step answer:
Let us first read about elements, compounds.
Elements: They are defined as the substance which cannot be further broken down into pieces. They are made of atoms which are of the same type. They are basically of two types: metals and non-metals. And also there is a third category which is known as metalloids (which shows the properties of metals as well as non-metals).
Compounds: The chemical species which are formed by two or more elements are known as compounds.
The relation between empirical formula and molecular formula is as follows:
${\text{Molecular formula = (Empirical formula}}{{\text{)}}_n}$ where $n$ is an integer.
Now here in the question we are given with the empirical formula and we have to find its molecular formula. Empirical formula is given as: $C{H_2}{O_2}$. So its molecular formula will be: ${(C{H_2}{O_2})_n}$ where $n$ is an integer value. So if value of $n$ is $2$ the molecular formula of the compound will be ${(C{H_2}{O_2})_2}$ i.e. ${C_2}{H_4}{O_4}$.

Hence option C is correct.

Note:
Here in the question the elements carbon, hydrogen and oxygen are in the ratio $1:2:2$. But in option A, B and D the ratio of these elements are as $2:2:2$, $2:2:4$ and $1:4:4$ respectively. So these options are not correct.