Question

What is not true about homologous series?
A.All members have similar chemical properties.
B.They have identical physical properties.
C.They can be represented by a common general formula.
D.Adjacent members differ in the molecular mass by \[14.\]

Answer 1

Hint: We know that the homologous series is a sequence of compounds which has the same functional group and same chemical properties in which the members of the series can be branched or unbranched. It can be the length of the carbon chain, for example in straight chain alkanes, or could be the number of monomers in a homopolymer.

Complete answer:
As we know that the word homologous describes itself as something that is common and similar in the series of organic compounds. One can think about the similarities and differences in properties such as physical and chemical properties as well as some structural changes which can be present in the series. A homologous series is a series of hydrocarbons which have similar chemical properties and they share the same general formula. They are organic compounds having similar structure and functional groups.
The term homologous series is also sometimes used for any collection or group of compounds that are similar in their structures or having the same functional group in their structures. Some compounds such as the general alkane, alkene and the carbohydrates, etc. show the presence of homologous series. Homologous series differ by a \[C{{H}_{2}}\] ​ group. It has a mass of \[14\] units. They can be represented by a common general formula for alkanes, alkenes, alkynes and other functional groups. As the molecular mass increases in a homologous series, a gradation in physical properties is observed.
Therefore, the correct answer is option B.

Note:
Remember that every member which is present in the homologous series shows different physical properties but they all show similar chemical properties due to the same functional group. Compounds of carbon can be arranged in a series of successive compounds showing a gradual change in physical properties of the constituents of the series or having a similar relation.