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

Which of the following halide shows highest reactivity towards $$\mathrm{S}_{\mathrm{N}} 1$$ reaction?

Which of the following halide undergoes hydrolysis on warming with water/aqueous $$\mathrm{NaOH}$$ ?