The gas evolved by the reaction of ethyl iodide with alcoholic $KOH$,which decolorizes basic $KMnO_4$ solution,is........

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

The reaction $R-CH=CH_2 \xrightarrow{Na/NH_3, C_2H_5OH} R-CH_2CH_3$ is known as:

The major product of the reaction of $2-$butene with cold alkaline $KMnO_4$ is:

Give the increasing order of stability for the following alkenes based on their heat of hydrogenation $(\Delta H^o)$:
$(I) (CH_3)_2C = C(CH_3)_2$
$(II) CH_3CH_2CH_2CH = CH_2$
$(III) (CH_3)_2C = CHCH_3$
$(IV) CH_3CH_2C(CH_3) = CH_2$

The major product of the following chemical reaction is: $CH_3-CH(CH_3)-CH=CH_2 + HBr \xrightarrow{(C_6H_5CO)_2O_2} ?$