The alkene which on ozonolysis yields acetone is

$17 \, mg$ of a hydrocarbon ($M$.$F$. $C_{10}H_{16}$) takes up $8.40 \, mL$ of $H_2$ gas measured at $0^{\circ}C$ and $760 \, mm$ of $Hg$. Ozonolysis of the same hydrocarbon yields acetone,formaldehyde,and a compound with the structure $CH_3-CO-CH_2-CH_2-CHO$. The number of double bonds present in the hydrocarbon is $...........$.

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

Ethylene reacts with Baeyer's reagent to give

What is the product of the following reaction?
$1,2-\text{dimethylcyclopentene} \xrightarrow[2. NaHSO_3]{1. OsO_4} \text{Product}$

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