The presence of unsaturation in organic compounds can be tested with

Which one of the following compounds gives acetone $(CH_3)_2C=O$ as one of the products of its ozonolysis?

The given reaction represents the ozonolysis of an alkene $A$. Identify $A$ and the product $B$ in the following reaction sequence:
$A + O_3$ $\rightarrow \text{ozonide intermediate}$ $\xrightarrow{Zn + H_2O} B + HCHO$

Which of the following is most reactive for electrophilic addition reaction?

The stereochemistry of the product formed in the following reaction is:

The major product of the reaction of $2$-butene with alkaline $KMnO_4$ solution is