Question

The difference in molecular weight of two consecutive members of homologous series is

• A. $15$
• B. $14$
• C. $8$
• D. $9$

Answer 1

The correct option is B

$14$

Explanation for correct option:

(B) $\mathbf{14}$:

Homologous series refers to a set of organic compounds that have similar structural properties but differ from other members by the $-{\mathrm{CH}}_2$ group. For example, Methane $\left({\mathrm{CH}}_4\right)$, Ethane $\left({\mathrm{C}}_2{\mathrm{H}}_6\right)$, propane $\left({\mathrm{C}}_3{\mathrm{H}}_8\right)$, etc.

They have the same general formula and share the same functional group; therefore, their chemical characteristics are similar, but their physical properties differ due to differences in mass. The difference between two consecutive members of a homologous series is $-{\mathrm{CH}}_2$, resulting in a molecular weight difference of $14.$.

Hence, (B) is the correct option.

Explanation for incorrect options:

Since, the correct difference in molecular weight of two consecutive members of homologous series is$\mathbf{14}$. Therefore, all the other options (A), (C), and (D) are incorrect.

Final answer:

Therefore, the correct option is (B) $\mathbf{14}$.