Question

question
what is the condensed formula notation for 3 - ethyl - 4 - methylnonane?
select the correct answer below:
○ ch₃ - ch₂ - ch(ch₂ch₃) - ch(ch₃) - ch₂ - ch₂ - ch₂ - ch₃
○ ch₃ - ch₂ - ch(ch₂ch₃) - ch(ch₃) - ch₂ - ch₂ - ch₂ - ch₂ - ch₃
○ ch₃ - ch₂ - ch(ch₂ch₃) - ch(ch₃) - ch₂ - ch₂ - ch₃
○ ch₃ - ch₂ - ch(ch₃) - ch(ch₂ch₃) - ch₂ - ch₂ - ch₂ - ch₂ - ch₃

Explanation:

Step1: Analyze parent - chain

Nonane has 9 - carbon parent - chain with formula $\mathrm{C}_{9}\mathrm{H}_{20}$.

Step2: Locate substituents

Ethyl group ($\mathrm{-CH}_{2}\mathrm{CH}_{3}$) at 3 - position and methyl group ($\mathrm{-CH}_{3}$) at 4 - position.

Step3: Write condensed formula

Starting from one end of the chain, we get $\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}(\mathrm{CH}_{2}\mathrm{CH}_{3})-\mathrm{CH}(\mathrm{CH}_{3})-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{3}$.

Answer:

B. $\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}(\mathrm{CH}_{2}\mathrm{CH}_{3})-\mathrm{CH}(\mathrm{CH}_{3})-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{3}$