Chapter 19, Problem 1CE

Interpretation Introduction

Interpretation:

Among the compounds decane $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{22}}\right)$, decene $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{20}}\right)$, decyne $\left({\text{C}}_{\text{10}}{\text{H}}_{18}\right)$, and naphthalene $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{8}}\right)$ the one that is an alkane is to be identified.

Concept introduction:

Hydrocarbons are the compounds that contain only carbon and hydrogen in the molecular formula. Alkanes are hydrocarbons containing single bonds only. The hydrocarbons containing no multiple bonds are known as saturated hydrocarbons.

Answer to Problem 1CE

The compound decane $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{22}}\right)$ is an alkane.

Explanation of Solution

The general formula for an alkane containing only single bonds is shown below.

${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$

Where,

• n is the number of carbon atoms.

Therefore, all the compounds obeying this formula are alkanes. In general, the compound having the hydrogen atoms two more than twice the number of carbon atoms is an alkane. Also, the compounds those are alkane have suffix “-ane” in their names.

All the compounds, decane $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{22}}\right)$, decene $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{20}}\right)$, decyne $\left({\text{C}}_{\text{10}}{\text{H}}_{18}\right)$, and naphthalene $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{8}}\right)$ contain the same number of carbon atoms in their molecular formula.

The compound decane $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{22}}\right)$ has its name ending with the suffix “-ane” and also the number of hydrogen are two more than twice the number of carbon atoms.

The number of carbon atoms are ten in the molecular formula. Therefore, the number of hydrogen atoms should be $22\left(2\times 10+2=22\right)$ that are present in the molecular formula.

The other compounds, decene $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{20}}\right)$, decyne $\left({\text{C}}_{\text{10}}{\text{H}}_{18}\right)$, and naphthalene $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{8}}\right)$ does not have their suffix matching with that of an alkane. Also, the number of hydrogen atoms in the compounds are also not matching with the number of hydrogen atoms that should be present in a ten carbon containing alkane.

Conclusion

The compound decane $\left({\text{C}}_{\text{10}}{\text{H}}_{\text{22}}\right)$ is an alkane.