Chapter 10, Problem 3STP

Interpretation Introduction

Interpretation: The empirical formula for tartaric acid should be identified.

Concept Introduction: An empirical formula represents the various atoms in a compound in the simplest whole-number ratio. It does not represent the actual number or arrangement of atoms in a compound.

Answer to Problem 3STP

Correct answer: option (A) ${\text{C}}_2{\text{H}}_3{\text{O}}_3$ .

Explanation of Solution

Reason for the correct option:

The given structural formula of tartaric acid is:

  

Determining the correct molecular formula of the tartaric acid by calculating the number of atoms of each element present in tartaric acid as:

  $\begin{array}{l}\text{C = 4}\hfill \\ \text{H = 6}\hfill \\ \text{O = 6}\hfill \end{array}$

So, the molecular formula of tartaric acid is, ${\text{C}}_{\text{4}}{\text{H}}_{\text{6}}{\text{O}}_{\text{6}}$ .

Now to determine the empirical formula, the subscripts of the molecular formula are reduced to the simplest whole-number ratio:

  ${\text{C}}_{\frac{\text{4}}{2}}{\text{H}}_{\frac{6}{2}}{\text{O}}_{\frac{6}{2}}{\text{ = C}}_2{\text{H}}_3{\text{O}}_3$

Hence, the empirical formula for tartaric acid is ${\text{C}}_2{\text{H}}_3{\text{O}}_3$ .