Level 3

Among the following.

I 

II 

III 

IV 

V 

The antiaromatic compounds are

It is difficult to esterify ${\mathrm{R}}_3\mathrm{C}-\mathrm{COOH}$ because of:

Two isomeric compounds $\mathrm{I}$ and $\mathrm{II}$ are heated with $\mathrm{HBr}$.

The products obtained are

The ammonia evolved from $2 \mathrm{g}$ of a compound in Kjeldahl's estimation of nitrogen neutralizes $10 \mathrm{mL}$ of $2 \mathrm{M}$ ${\mathrm{H}}_2{\mathrm{SO}}_4$ solution. The weight percentage of nitrogen in the compound is:

The correct order of the increasing basic nature of the following base is

In which of the following pairs of carbocations, the first carbocation is more stable than the second?
($\mathrm{i}$) ${\mathrm{CH}}_2=\mathrm{CH}-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2$ and ${\mathrm{CH}}_2=\mathrm{CH}-{\mathrm{CH}}_2-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2$
($\mathrm{ii}$) ${\mathrm{CH}}_3-\mathrm{NH}-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2$ and $\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2-\mathrm{OH}$
($\mathrm{iii}$) ${\mathrm{CH}}_3-\mathrm{O}-{\mathrm{CH}}_2-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2$ and ${\mathrm{CH}}_3-\mathrm{O}-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2$
($\mathrm{iv}$) ${\mathrm{CH}}_3-\stackrel{+}{\mathrm{C}}\mathrm{H}-{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_3$ and ${\mathrm{CH}}_3{\mathrm{CH}}_2-\stackrel{+}{\mathrm{C}}\mathrm{H}-{\mathrm{CH}}_2{\mathrm{CH}}_3$

Among formic acid, acetic acid, propanoic acid and phenol, the strongest acid in water is:

The most acidic proton and the strongest nucleophilic nitrogen in the following compound respectively, are: