In the following pairs of halogen compounds, which compound undergoes faster $$S_N 1$$ reaction?

Which one of the following chlorohydrocarbon readily undergoes solvolysis?

Peroxide effect is observed with the addition of $$\mathrm{HBr}$$ but not with the addition of HI to unsymmetrical alkene because

The order of reactivity of the compounds $$\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{Br}, \mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}\left(\mathrm{C}_6 \mathrm{H}_5\right) \mathrm{Br}, \mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}\left(\mathrm{CH}_3\right) \mathrm{Br}$$ and $$\mathrm{C}_6 \mathrm{H}_5 \mathrm{C}\left(\mathrm{CH}_3\right)\left(\mathrm{C}_6 \mathrm{H}_5\right) \mathrm{Br}$$ in $$\mathrm{S}_{\mathrm{N}} 2$$ reaction is