Identify the reagent R used in following conversion?

tert-butyl bromide $\xrightarrow{\mathrm{R}}$ Isobutylene

Identify the correct stability order of following alkenes.

I) $\left(\mathrm{CH}_3\right)_2 \mathrm{C}=\mathrm{C}\left(\mathrm{CH}_3\right)_2$

II) $\left(\mathrm{CH}_3\right)_2 \mathrm{C}=\mathrm{CH}_2$

III) $\left(\mathrm{CH}_3\right)_2 \mathrm{C}=\mathrm{CHCH}_3$

Identify the product of ozonolysis of but-2-ene from following:

Identify the product ' B ' in the following reaction sequence.

$$\mathrm{C}_2 \mathrm{H}_5-\mathrm{Br} \xrightarrow[\text { Dry ether }]{\mathrm{Mg}} \mathrm{~A} \xrightarrow{\mathrm{CH}_3 \mathrm{OH}} \mathrm{~B}$$