Calculate half life of first order reaction if rate constant of reaction is $$2.772 \times 10^{-3} \mathrm{~s}^{-1}$$

Which among the following is NOT colligative property?

Identify the reaction in which carbonyl group of aldehydes and ketones is reduced to methylene group on treatment with hydrazine followed by heating with sodium hydroxide in ethylene glycol.

Identify the product '$$\mathrm{B}$$' in the following reaction. Toluene $$\xrightarrow[\mathrm{CS}_2]{\text { Chromylchloride }} \mathrm{A} \xrightarrow{\mathrm{H}_3 \mathrm{O}^{+}}\mathrm{B}$$