Question

State Huckel's rule with suitable examples of aromatic character.

Answer 1

Hint: To get this problem solved you need to know about huckel's rule and about pie electrons. Pie electrons are those which are present where there is double and triple bond or a conjugated p-orbital. Knowing this will solve your problem and will give you the right answers.

Complete step-by-step answer:
Huckle rule: Huckel 's Law is used to estimate the aromatic qualities of any flat ring-shaped molecule in the field of organic chemistry. In 1931, the German physical chemist and physicist Erich Armand Arthur Joseph Huckel resolved the supporting quantum mechanics needed for the formulation of this law.

4n+2 is not the formula you are adding to see if the molecule is aromatic. It's a formula that tells you what the numbers in the magic sequence are. If your pi electron value matches every number in this sequence, you have the right for aromaticity.
In Huckle’s rule there are always (4n+2)pie electrons.
In the Cyclic planar system all the carbon is $sp^2$ hybridized.

Note – Knowing this will help you to know the aromaticity of the compound and will help you to solve the problems further. The ring-shaped cyclic molecule is said to obey the Huckel rule when the total number of pi electrons belonging to the molecule can be equalized to the formula '4n + 2' where n can be any integer with a positive value (including zero). Examples of molecules following Huckel 's law have only been developed for 'n' values ranging from zero to six. The total number of pi electrons in the benzene molecule shown below can be found to be 6, following the (4n+2) pie electron rule where n=1.