Resonance

Question 1

Evidence for resonance

Answer 1

All bond angles are equal
All C-C bond lengths are equal
All C-H bond lengths are equal
C-C bond length is between those of double and single bonds

Question 2

Resonance and equilibrium

Answer 2

Resonance does not mean equilibrium

Averaging effect rather than rapid alternation

Question 3

Conjugated

Answer 3

Having a mixture of single and multiple bonds

Question 4

Aromaticity

Answer 4

The delocalisation of 6 𝛑 electrons around a ring
e.g. Benzene
2/3 of 100 million are aromatic
Special stability - less reactive

Question 5

Aromatic Heterocycles

Answer 5

Ring is broken by N atom

Question 6

Rules of resonance

Answer 6

1. are imaginary
2. Are less stable than the resonance hybrids
3. differ only in their position of their 𝛑 or non-bonding electrons
4. need not be equivalent
5. obey the normal rules of valency