Q. 2.3.1

Determine the molecular and empirical formulas for the following substances.
a. Hexane, a laboratory solvent

$\begin{matrix}\quad \quad \quad \enspace \underset{|}{H} \enspace \enspace \underset{|}{H} \enspace \;\; \underset{|}{H}\enspace \enspace \underset{|}{H}\enspace \enspace \;\underset{|}{H} \enspace \enspace \;\underset{|}{H} \; \\ \qquad \quad H-\underset{|}{C}-\underset{|}{C}-\underset{|}{C}-\underset{|}{C}-\underset{|}{C}-\underset{|}{C} -H \\\enspace \enspace\; \enspace \enspace \enspace H\enspace \enspace H\enspace \enspace H\enspace \enspace H\enspace \enspace H\enspace \enspace H \end{matrix}$

b. Butyraldehyde, a compound used for synthetic almond flavoring in food

$\begin{matrix}\quad \quad \enspace \underset{|}{H}\quad \underset{|}{H} \quad \underset{|}{H} \quad \underset{||}{O} \\\quad \quad \enspace H-\underset{|}{C}-\underset{|}{C}-\underset{|}{C}-{C} -H \\H\quad H\quad H \end{matrix}$

Verified Solution

You are asked to write the empirical and molecular formulas for a compound.
You are given the formula of the compound.
a. A hexane molecule contains 6 carbon atoms and 14 hydrogen atoms. The molecular formula of hexane is C$_{6}$H$_{14}$. The empirical formula, the simplest whole-number ratio of elements in the compound, is C$_{3}$H$_{7}$.
b. A butyraldehyde molecule contains four carbon atoms, eight hydrogen atoms, and one oxygen atom. The molecular formula of butyraldehyde is C$_{4}$H$_{8}$O. In this case, the empirical formula, the simplest whole-number ratio of elements in the compound, is the same as the molecular formula, C$_{4}$H$_{8}$O.