The number of alkene isomers with the molecular formula $C_4H_8$ is ....

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

Two isomers $A$ and $B$ with molecular formula $C_4H_8$ give different products on oxidation with $KMnO_4$ in acidic medium. Isomer $A$ on reaction with $KMnO_4 / H^{+}$ results in effervescence of a gas and gives a ketone. The compound $A$ is ...... .

Identify $X, Y$ and $Z$ in the following reactions:

Which of the following reactions results in the formation of a pair of diastereomers?

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