Chemistry - GOC Question with Solution | TestHub
Find the number of compounds which contain at least one nitrogen atom with a localised lone pair and at least one nitrogen atom with a delocalised lone pair.
(i) 
(ii) 
(iii) 
(iv) 
(v) 
(vi) 
(vii) 
(viii) 
(ix) 
Answer:
Solution:
(i) Imidazole: (delocalised) and pyridine-type N (localised): yes. (ii) Pyrimidine: both N are pyridine-type, only localised: no. (iii) Indole: one , only delocalised: no. (iv) 2-Aminopyridine: ring N localised, delocalised into the ring: yes. (v) Adenine: ring N atoms localised, and delocalised: yes. (vi) N-Methylaniline: one N, delocalised only: no. (vii) Acetamidine: =NH localised, delocalised (amidine resonance): yes. (viii) Quinuclidine: one N, localised only: no. (ix) Pyrazole: delocalised and pyridine-type N localised: yes.
Total: (i), (iv), (v), (vii), (ix) = 5.
Answer: 5.
