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

Given below are two statements $:$
Statement $I :$ Ozonolysis followed by treatment with $Zn, H_2O$ of $cis-2-butene$ gives ethanal.
Statement $II :$ The product obtained by ozonolysis followed by treatment with $Zn, H_2O$ of $3,6-dimethyloct-4-ene$ has no chiral carbon atom.
In the light of the above statements,choose the correct answer from the options given below.

Give the chemical reactions for the following conversions:
$(1)$ Glyoxal from acetylene
$(2)$ Glycol from bromoethane

In the given reaction,$X$ will be:
Cyclohexene $\xrightarrow{NBS}$ $\xrightarrow[ether]{Mg}$ $\xrightarrow[2.H^{+}]{1.CO_2} X$

Oils are converted into fats by

Addition of $BH_3$ followed by $H_2O_2$ to $trans-2-butene$ would give a product which is