Resonance

For phenol, which of the following resonating structure is the most stable?

${\text{C}\text{H}}_2=\text{CH}-\text{C}\text{H}=\text{C}\text{H}-{\text{CH}}_3$ is more stable than ${\text{CH}}_3-\text{CH}=\text{C}=\text{CH}-{\text{CH}}_3$ because

Among these canonical structures, the correct order of stability is

$\left(\text{I}\right){\text{CH}}_2=\text{CH}-\text{CH}={\text{CH}}_2$

$\left(\text{I}\text{I}\right){\stackrel{\ominus }{\text{C}}\text{H}}_2-\text{CH}=\text{CH}-\stackrel{\oplus }{\text{C}}{\text{H}}_2$

$\left(\text{I}\text{I}\text{I}\right){\stackrel{\oplus }{\text{C}}\text{H}}_2-\text{CH}=\text{CH}-\stackrel{\ominus }{\text{C}}{\text{H}}_2$

Among, these, which are canonical structures?

Which species has the bond order is equal to $1.33.$

Resonance structures are not considered isomers. Why?

Which statement is true? 

Dispel some misconceptions associated with resonance?

Write the difference between Resonance and isomerism.

Which of the following resonating structure is most stable?

Write the following statement of about RESONANCE are true or false.

There is no equilibrium between the canonical forms.

Write the following statement of about RESONANCE are true or false.

The molecule does exist for a certain fraction of time in one canonical form and for other fractions of time in other canonical forms.

State if the following statements about RESONANCE are true or false.

Canonical forms of any structure have no real existence.

The bond order of$\mathrm{N}–\mathrm{O}$ bonds in ${\mathrm{NO}}_3^{-}$  ion is

Assertion. The resonance hybrid is more stable than any of the contributing structure.

Reason. The contributing structures contain the same number of unpaired electrons and have real existence.

Consider the following resonating structure. What will be the correct decreasing order of stability?

Which of the given options represents the correct order of $\mathrm{C}-\mathrm{N}$ bond length in the following amines?

$\left(\mathrm{I}\right)$ ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2-\stackrel{..}{\mathrm{N}}{\mathrm{H}}_2$

$\left(\mathrm{II}\right)$ ${\mathrm{CH}}_2=\mathrm{CH}-\stackrel{..}{\mathrm{N}}{\mathrm{H}}_2$

$\left(\mathrm{III}\right)$

Which of the following molecule has longest $\mathrm{C}=\mathrm{C}$ bond length?

Cotyledons are also called-

Which of the following statements are correct for butadiene

$\stackrel{4}{\mathrm{C}}{\mathrm{H}}_2=\stackrel{3}{\mathrm{C}}\mathrm{H}-\stackrel{2}{\mathrm{C}}\mathrm{H}=\stackrel{1}{\mathrm{C}}{\mathrm{H}}_2$

(1) The ${\mathrm{C}}_1-{\mathrm{C}}_2$ and ${\mathrm{C}}_3-{\mathrm{C}}_4$ bonds are longer than a carbon-carbon double bond.

(2) The ${\mathrm{C}}_1-{\mathrm{C}}_2$ and ${\mathrm{C}}_3-{\mathrm{C}}_4$ bonds are shorter than a carbon-carbon double bond.

(3) The ${\mathrm{C}}_2-{\mathrm{C}}_3$ bond is slightly shorter than a carbon-carbon single bond.

(4) The ${\mathrm{C}}_2-{\mathrm{C}}_3$ bond is slightly longer than a carbon-carbon single bond.