Explain the following:
I. Which of the following is more easily enolised?
a. Cyclobutenone
b. Triketo cyclobutane
II. Why are keto forms of 2-pyridinol and `4`-pydridinol more stable than enol form?
III. Why is keto form generally much stable than enol form?
IV. Why is enol content of butane `-2,3` dione(biacetyl) `(A)` slightly higher than that of butan-2 one `(B)` and much less than that of cyclohexane `-1,2-` dione`(C )`