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Hydrocarbons — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistryHydrocarbons1 Mark
MCQ
In the following questions a statement of assertion $(A)$ followed by a statement of reason $(R)$ is given. Choose the correct option out of the choices given below each question.
Assertion $(A)$ : The compound cyclooctane has the following structural formula:

It is cyclic and has conjugated $8\pi-$ electron system but it is not an aromatic compound.
Reason $(R) : (4n + 2) \pi-$ electrons rule does not hold good and ring is not planar.
  • ✓
    $A$ and $R$ both are correct, and $R$ is the correct explanation of $A.$
  • B
    $A$ and $R$ both are correct, but $R$ is not the correct explanation of $A$.
  • C
    $A$ is true but $R$ is false.
  • D
    $A$ and $R$ both are false.
✓

Answer

Correct option: A.
$A$ and $R$ both are correct, and $R$ is the correct explanation of $A.$
Both $A $ and $R$ are Correct, and $R$ is correct explanation of $A$.
Aromaticity is shown by compounds possessing following characteristics:
Planarity. Complete delocalization of the $\pi$ electrons in the ring.
Presence of $(4n + 2)\pi$ electrons in the ring where n is an integer $(4 = 0, 1, 2, .....)$.
This is often referred to as Huckel Rule.

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