Check sibling questions

Which of the following is not observed in a homologous series? Give reason for your choice.

(a) Change in chemical properties

(b) Difference in —CH 2 and 14u molecular mass

(c) Gradation in physical properties

(d) Same functional group

 

Answer

Homologous Series - Teachoo.png

Homologous series is a group/sequence of compounds which have the same functional group and similar chemical properties . The two successive compounds differ by a CH 2 group i.e. 12 + (2 x 1) = 14 amu.

In a homologous series, only the physical properties change . Chemical properties remain the same because of the presence of the same functional group.

Now, let’s check the options

  • (a) Change in chemical properties  - This is not observed in a homologous series. The chemical properties of all compounds in a homologous series remain the same.
  • (b) Difference in —CH 2 and 14u molecular mass  - This is observed in a homologous series.
  • (c) Gradation in physical properties - This is observed in a homologous series.  
  • (d) Same functional group - This is observed in a homologous series.  

Therefore, the correct option is (a) change in chemical properties  


Transcript

Which of the following is not observed in a homologous series? Give reason for your choice. (a) Change in chemical properties (b) Difference in —CH2 and 14u molecular mass (c) Gradation in physical properties (d) Same functional group Answer Homologous Series Alkanes Alkynes Alcohols CH4 C2H6 C3H8 C4H10 CH2 CH2 CH2 C2H2 C3H4 C4H6 C5H8 CH2 CH2 CH2 CH3OH C2H5OH C3H7OH C4H9OHCH2 CH2 CH2 CH2 Homologous series is a group/sequence of compounds which have the same functional group and similar chemical properties. The two successive compounds differ by a CH2 group i.e. 12 + (2 x 1) = 14 amu. In a homologous series, only the physical properties change. Chemical properties remain the same because of the presence of the same functional group. Now, let’s check the options (a) Change in chemical properties - This is not observed in a homologous series. The chemical properties of all compounds in a homologous series remain the same. (b) Difference in —CH2 and 14u molecular mass - This is observed in a homologous series. (c) Gradation in physical properties - This is observed in a homologous series. (d) Same functional group - This is observed in a homologous series. Therefore, the correct option is (a) change in chemical properties

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CA Maninder Singh is a Chartered Accountant for the past 12 years and a teacher from the past 16 years. He teaches Science, Accounts and English at Teachoo