What is the major product expected from the following reaction?

Which of the following alkenes reacts fastest with $H_2$ under catalytic hydrogenation conditions?

An alkene $X$ $(C_6H_{12})$ on ozonolysis gives acetaldehyde and ethyl methyl ketone. What is the product formed when $X$ reacts with $HBr$?

Which of the following aliphatic compounds will discharge the red colour of bromine?

$LDA = \text{Lithium di-isopropyl amide}$. In the given reaction,identify product $A$:

The number of alkene$(s)$ which can produce $2-butanol$ by the successive treatment of $(i)$ $B_{2}H_{6}$ in tetrahydrofuran solvent and $(ii)$ alkaline $H_{2}O_{2}$ solution is: