Read the passage and answer the following questions. (4m)
A homologous series is a series of organic compounds which belong to the same family i.e.
possess the same functional group and show similar chemical properties. The members of this
series are called homologous and differ from each other by the number of CH2 units in the main
carbon chain.
(A) The chemical properties of which of the following compounds is similar to the Butane?
(I) butyne (II) propene (III) propyne (Iv) pentane
(B) What is the difference between two consecutive members in a homologous series in
alkanes in terms of :
(I) Molecular mass
(II) no of atoms of elements.
© The compound CH3CH(OH)CH3 belongs to which homologous series?
(D) which of the following is not the property of a homologous series:
(I) they show similar chemical properties.
(II) they differ by 14u by mass
(III) they all contain double bond
(iv) they can be represented by a general formula.
Answers
Answer:
homologous series is a series of compounds with the same functional group and similar chemical properties in which each successive member differs by CH
2
.Compounds within a homologous series typically have a fixed set of functional groups that gives them similar chemical and physical properties. The name "homologous series" is also often used for any collection of compounds that have similar structures or include the same functional group, such as the general alkanes (straight and branched), the alkenes (olefins), the carbohydrates, etc.
Here, CH4O and C2 H 6O are of same homologous series. Both arediffered by CH 2
Explanation:
A series of organic compounds that have similar structural features but differ from adjacent members by (−CH
2
) group is referred to as homologous series.
They have same general formula and because of a same functional group, they have similar chemical properties but due to varying mass, they have different physical properties.
Option D is correct.