Question

The compound with molecular formula C\(_6\)H\(_6\), which gives only one monobromo derivative and takes up four moles of hydrogen per mole for complete hydrogenation has \(\_\_\_\_\_\)\( \pi \) electrons. 

Hint:

Aromatic compounds like benzene (C\(_6\)H\(_6\)) have a conjugated system of \( \pi \)-electrons that satisfy Hückel's rule, which states that aromatic compounds have 4n + 2 \( \pi \)-electrons (where n is a whole number).

Answer 1

Correct Answer: 6

Benzene, molecular formula C\(_6\)H\(_6\), is a recognized aromatic compound. Its structure is a planar ring of carbon atoms with delocalized pi electrons due to alternating single and double bonds, creating a conjugated system. Each carbon-carbon double bond contributes 2 \( \pi \)-electrons. With 6 carbon atoms involved in conjugation, the total count of \( \pi \)-electrons in benzene is 6. Therefore, the result is: \[\text{The number of } \pi \text{ electrons} = 6\]