Which of the following tests may be used to distinguish between phenol and cyclohexanol?

Arrange the following compounds in the decreasing order of their acidic strength.

(I) m-cresol

(II) Phenol

(III) m-aminophenol

(IV) m-methoxyphenol

Which of the following compound cannot be prepared by Williamson's synthesis?

An organic compound $$[\mathrm{A}]\left(\mathrm{C}_5 \mathrm{H}_{12} \mathrm{O}\right)$$, on reaction with conc. $$\mathrm{H}_2 \mathrm{SO}_4$$ at $$443 \mathrm{~K}$$ gives $$[\mathrm{B}]$$ as one of the products. Compound [B] undergoes further reaction with $$\mathrm{O}_3$$ and $$\mathrm{Zn} / \mathrm{H}_2 \mathrm{O}$$ to give Propanone and Ethanal as products. Identify compound [A]