Which of the following is most basic?

The number of secondary amines with the molecular formula $C_4H_{11}N$ is

Assertion : Benzene diazonium salt on boiling with water forms phenol.
Reason : $C-N$ bond is polar.

What is obtained upon the reduction of $t$-butyl isocyanide?

State True or False for the following statements:
$(i)$ Aniline becomes polar in its resonance structure.
$(ii)$ The separation of charge occurs in the resonance structure of aniline.
$(iii)$ The $NH_2$ group of aniline is electron donating.
$(iv)$ The $NH_2$ group of aniline is electron attracting in resonance $(-R)$.

The reaction $C_6H_5NH_2 + CHCl_3 + 3KOH \to C_6H_5NC + 3KCl + 3H_2O$ is known as