Chapter 23, Problem 30PS

Interpretation Introduction

Interpretation:

Elemental analysis of a colourless liquid has given its formula as ${\text{C}}_{\text{5}}{\text{H}}_{\text{10}}$. Recognize that this could be either a cycloalkane or an alkene. A chemical test to determine the class to which this compound belongs to involves adding bromine. The way in which the two classes are distinguished using the above method should be explained.

Concept introduction:

Alkenes are the hydrocarbons which have a genral molecular formula ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$. Alkenes are consist of double bond (one pi bond) due to which they are known as unsaturated hydrocarbons.

The hydrocarbons which have ring structure with a molecular ${\text{C}}_n{\text{H}}_{2n}$ are known as Cycloalkanes. Cycloalkanes can be substituted or unsubstituted, when carbon atom is substituted are known as substituted Cycloalkanes or branched Cycloalkanes. A Cycloalkane can be formed when carbon number is more than two.  In formula, $n$ is the total number of carbon atoms present in molecule. For example if $n$ is equal to $4$ than molecular formula will be ${\text{C}}_{\text{4}}{\text{H}}_{\text{8}}$.