The bond length of the $C-H$ bond in ethene is ...... $pm$.

$CH_2=CHCl$ reacts with $HCl$ to form

Propanal and pentan-$3$-one are the ozonolysis products of an alkene. What is the structural formula of the alkene?

Identify the major products $X$ and $Y$ in the following reactions:
$(i)$ $C_6H_5-CH=CH_2 + HBr \rightarrow X$
(ii) $C_6H_5-CH_2-CH=CH_2 + HBr \xrightarrow{\text{Peroxide}} Y$

$Propanal$ and $pentan-3-one$ are ozonolysis products of:

In the reaction with $HCl$,an alkene reacts in accordance with the Markovnikov's rule to give a product $1-$chloro$-1-$methylcyclohexane. The possible alkene is