The correct structural formula of Butanoic acid is

Mineral acids are stronger acids than carboxylic acids because

(i) mineral acids are completely ionised.

(ii) carboxylic acids are completely ionised.

(iii) mineral acids are partially ionised.

(iv) carboxylic acids are partially ionised.

Which among the following are unsaturated hydrocarbons?

(i) ${\mathrm{H}}_3\mathrm{C}—{\mathrm{CH}}_2—{\mathrm{CH}}_2—{\mathrm{CH}}_3$

(ii) ${\mathrm{H}}_3\mathrm{C}—\mathrm{C}\equiv \mathrm{C}—{\mathrm{CH}}_3$

(iii) ${\mathrm{H}}_3\mathrm{C}—\underset{\stackrel{|}{{\mathrm{CH}}_3}}{\mathrm{CH}}—{\mathrm{CH}}_3$

(iv) ${\mathrm{H}}_3\mathrm{C}—\underset{\stackrel{|}{{\mathrm{CH}}_3}}{\mathrm{C}}={\mathrm{CH}}_2$