(a) (i) Write the reaction involved in Cannizaro's reaction.

(ii) Why are the boiling point of aldehydes and ketones lower than that of corresponding carboxylic acids?

(iii) An organic compound '$$\mathrm{A}$$' with molecular formula $$\mathrm{C}_5 \mathrm{H}_8 \mathrm{O}_2$$ is reduced to $$\mathrm{n}$$-pentane with hydrazone followed by heating with $$\mathrm{NaOH}$$ and Glycol. 'A' forms a dioxime with hydroxylamine and gives a positive Iodoform and Tollen's test. Identify '$$A$$' and give its reaction for Iodoform and Tollen's test.

OR

(b) (i) Give a chemical test to distinguish between ethanol acid and ethanoic acid.

(ii) Why is the $$\alpha$$-hydrogens of aldehydes and ketones are acidic in nature?

(iii) An organic compound '$$\mathrm{A}$$' with molecular formula $$\mathrm{C}_4 \mathrm{H}_8 \mathrm{O}_2$$ undergoes acid hydrolysis to form two compounds '$$\mathrm{B}$$' and '$$\mathrm{C}$$'. Oxidation of '$$C$$' with acidified potassium permanganate also produces 'B'. Sodium salt of 'B' on heating with soda lime gives methane.

(1) Identify 'A', 'B' and 'C'.

(2) Out of 'B' and 'C', which will have higher boiling point? Give reason.

(a) Why is chemistry of actinoids complicated as compared to lanthanoids?

(b) Complete the following reaction and justify that it is a disproportionation reaction:

$$3 \mathrm{MnO}_4^{2-}+4 \mathrm{H}^{+} \rightarrow$$________ $$+$$ _________ $$+$$ $$\mathrm{H}_2 \mathrm{O}$$.

(c) The given graph shows the trends in melting points of transition metals:

Explain the reason why $$\mathrm{Cr}$$ has highest melting point and manganese $$(\mathrm{Mn})$$ a lower melting point.