Question 14 Marks
A series of organic compounds having the same functional group, with similar or almost identical chemical characteristics in which all the members can be represented by the same general formula and the two consecutive members of the series differ by $-\mathrm{CH}_{2}$, group or 14 mass unit in their molecular formulae is called a homologous series. For example, all the members of the alcohol family can be represented by the general formula, $\mathrm{C}_{n} \mathrm{H}_{2 n+1} \mathrm{OH}$ where, $n$ may have the values $1,2,3, \ldots$ etc. The various members of a particular homologous series are called homologues. The physical properties such as density, melting point, boiling point, solubility, etc. of the members of a homologous series show almost regular variation in ascending or descending the series.
i. Write two characteristics of homologous series.
ii. What are the fourth and fifth members of the alcohol homologous series? Write their name with the formula.
iii. Draw structure of Butanol.
OR
What is heteroatom?
i. Write two characteristics of homologous series.
ii. What are the fourth and fifth members of the alcohol homologous series? Write their name with the formula.
iii. Draw structure of Butanol.
OR
What is heteroatom?
Answer
View full question & answer→i. 1. All the members of a homologous series can be represented by same general formula.
2. All the members of homologous series show similar chemical properties.
ii. Fourth member is butanol $\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{OH}$.
Fifth member is pentanol $\mathrm{C}_{5} \mathrm{H}_{11} \mathrm{OH}$
OR
An organic compound having atom other than carbon and hydrogen is called hetroatom.
2. All the members of homologous series show similar chemical properties.
ii. Fourth member is butanol $\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{OH}$.
Fifth member is pentanol $\mathrm{C}_{5} \mathrm{H}_{11} \mathrm{OH}$
OR
An organic compound having atom other than carbon and hydrogen is called hetroatom.
