Chapter 20, Problem 60A

Interpretation Introduction

Interpretation: The general formula for an alkane needs to be written. Also, the difference in the following members of the series of the alkene needs to be explained.

Concept Introduction: Alkanes are the saturated hydrocarbons which are mainly composed of C and H atoms. The carbon atoms are bonded in straight chain or branched chain. Alkyl halides are the halogens derivatives of alkanes. They have certain heteroatoms as Cl, I, Br or F along with C and H atoms.

Answer to Problem 60A

General formula = $\text{C}\text{H}{}_{\text{2n+2}}$

Difference in two consecutive members = ${\text{CH}}_{\text{2}}$

Explanation of Solution

Alkanes are saturated hydrocarbons which are mainly composed of C and H atoms. Since each C can form 4 covalent bonds and H can form 1 bond therefore in alkane, each C must be bonded single covalent bond with other C atoms and H atoms. Thus the general formula of alkane must be $\text{C}\text{H}{}_{\text{2n+2}}$ .

The homologous series of alkanes is the sequence of alkanes with one more C atom in the molecule. Thus each member differs from previous or following member with ${\text{CH}}_{\text{2}}$ unit.

Conclusion

General formula = $\text{C}\text{H}{}_{\text{2n+2}}$

Difference in two consecutive members = ${\text{CH}}_{\text{2}}$