Which of the following carbocations is least stable?

Arrange the carbanions,$(CH_3)_3\overline{C}$,$\overline{C}Cl_3$,$(CH_3)_2\overline{C}H$,$C_6H_5\overline{C}H_2$ in order of their decreasing stability:

Which of the following carbocations is the most stable?

The correct order of stability of the given carbocations is:

Which of the following intermediates is not expected to be formed in the following reaction?

State True or False for the following statements:
$(i)$ Only carbocation is formed by homolytic cleavage of a bond.
$(ii)$ By heterolytic cleavage of a bond,a carbocation or carbanion is formed.
$(iii)$ The carbon of a carbanion is $sp^2$ and the carbon of a carbocation is $sp^3$.
$(iv)$ The carbon of a carbanion is $sp^3$ and the carbon of a carbocation is $sp^2$.