Chemistry Hydrocarbons BUMHS 2024
PMDC Verified Question 14 of 65
When a hydrogen atom of an alkane is removed, the resulting group is called ____?
A
Aryl
B
Alkyl
C
Alkenyl
D
Phenyl
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Alkyl
Concept:

Hydrocarbon fragments that attach to main chains or functional groups have specific nomenclature based on their parent molecule.

Solution:

  • An alkane has the general formula \( \text{C}_n\text{H}_{2n+2} \).


  • When one hydrogen atom is abstracted, the remaining fragment has the formula \( \text{C}_n\text{H}_{2n+1} \)-.


  • To name this group, the "-ane" suffix of the parent alkane is replaced with "-yl". Therefore, the resulting group is universally known as an alkyl group (represented by 'R').


  • For example: Methane (\( \text{CH}_4 \)) becomes a Methyl group (\( \text{CH}_3- \)).


Why other options are incorrect:

  • Aryl groups result from removing a hydrogen from an aromatic ring.


  • Phenyl is the specific aryl group derived from benzene (\( \text{C}_6\text{H}_6 \rightarrow \text{C}_6\text{H}_5- \)).


  • Alkenyl groups result from removing a hydrogen from an alkene (containing a double bond).

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