Decolourization of alkaline $KMnO_4$ is used as a test for

Which alkene undergoes ozonolysis to produce $2,6-$heptanedione?

$Ph-CH_2-CH(Br)-CH_2-CH_3 \xrightarrow{NaNH_2} (A)$
Total number of elimination products are (includes stereoisomers):

What will be the major product of each of the two reactions shown below?
$1.$ $CH_3-CH_2-CH(N^{+}(CH_3)_3)OH^{-} \xrightarrow{\text{heat}} CH_3-CH=CH-CH_3 (X) + CH_3-CH_2-CH=CH_2 (Y)$
$2.$ $CH_3-CH_2-CH(Br)-CH_3 \xrightarrow{\text{heat}} CH_3-CH=CH-CH_3 (X) + CH_3-CH_2-CH=CH_2 (Y)$

Ethene when treated with $Br_2$ in the presence of $CCl_4$,which compound is formed?

Complete the following reactions:
$(i)$ $C_2H_4 + O_2 \rightarrow$
$(ii)$ $4Al + 3O_2 \rightarrow$