Question

The empirical formula of acetic acid is:
A.$C{H_3}COOH$
B.${C_2}{H_4}O$
C.$C{H_2}O$
D.$CHO$

Answer 1

We can define the empirical formula of a compound is the entire number proportion of each type of atom in a compound. It could be similar to the compound’s molecular formula but not always. We could determine an empirical formula from data containing the weight of every element present in a compound or from the composition (given in terms of percentage).

Complete answer:
We have to remember that an empirical formula does not symbolize the association or number of atoms. It is distinguished for numerous ionic compounds like calcium chloride $\left( {CaC{l_2}} \right)$ , and macromolecules such as silicon dioxide $\left( {Si{O_2}} \right)$. The group of the molecule is the structural formula. The number of each kind of atom in a molecule is called a molecular formula.
The molecular formula of acetic acid is given as $C{H_3}COOH$. The definite whole number ratio in the order of $C:H:O$ is $2:4:2$ . The lowest simple whole-number ratio in the order of $C:H:O$ is $1:2:1$ . Hence, the empirical formula of acetic acid is $C{H_2}O$.
Therefore, the option (C) is correct.

Additional Information
The steps for obtaining the empirical formula of a given compound can be given as:
-Calculate the weight of each element given in grams.
-Determine the number of moles of each atom found.
-Split the number of moles of each element by the least amount of moles.
-Modify the numbers to whole numbers. The set of whole numbers given there as subscripts while writing the empirical formula.

Note:
One should not confuse between empirical formula, molecular formula, and structural formula. Molecular formula gives the number of atoms present in a compound. The structural formula gives the arrangement of molecules in the compound and the empirical formula is the whole number ratio of each kind of atom present in a compound.