An alkene,on ozonolysis,gives formaldehyde and acetaldehyde. The alkene is:

The products $Q$ and $R$ in the following reactions respectively are:
$H_2 + CH_3-C \equiv CH$ $\xrightarrow{\text{Lindlar's catalyst}} P$ $\xrightarrow[Zn + H_2O]{O_3} Q + R$

Cyclohexene is reacted with bromine in $CCl_4$ in the dark. The product of the reaction is,

Addition of $HI$ on the double bond of propene yields isopropyl iodide and not $n$-propyl iodide as the major product. This is because the addition proceeds through

The principal organic product formed in the following reaction is
$CH_2=CH(CH_2)_8COOH + HBr \xrightarrow{\text{peroxide}}$

$CH_3-C(CH_3)=CH_2$ $\xrightarrow[R_2O_2]{HBr} X$ $\xrightarrow{CH_3ONa} Y$; $X$ and $Y$ are: