Chapter 3, Problem 1SAQ

What is the empirical formula of a compound with the molecular formula $C_{10}{H}_8?$

$a)C_5{H}_3$

$b)C_2{H}_4$

$c)C_5{H}_4$

$d)CH$

Interpretation Introduction

Introduction: The formula that represents the ratio of elements present in the compound but not the actual number of atoms present in the molecule is called an empirical formula.

Answer to Problem 1SAQ

Correct answer: The correct answer is option $\left(\text{c}\right)$.

Explanation of Solution

Justify reason for correct option:

For the given compound ${\text{C}}_{10}{\text{H}}_8$, the subscripts are $10$ and $8$. These can be reduced further to the simplest form, on dividing by two as the common factor to obtain $5$ and $4$. Therefore, the correct empirical formula of the given compound is ${\text{C}}_5{\text{H}}_4$. Thus, option $\left(\text{c}\right)$ is the correct answer.

Justify reason for incorrect options:

In the other options, ${\text{C}}_{10}{\text{H}}_8$ cannot be reduced further to the simplest form other than $5$ and $4$. Thus, options $\left(\text{a}\right)\text{,}\left(\text{b}\right)\text{},\text{and}\left(\text{d}\right)$ are incorrect.

Conclusion: The correct empirical formula for the given compound ${\text{C}}_{10}{\text{H}}_8$ is ${\text{C}}_5{\text{H}}_4$.