Electrophilic addition on a carbon-carbon double bond involves the intermediate formation of a more stable carbocation. This statement is called

Ethyl phenyl acetylene ($1$-phenyl-but-$1$-yne) on reduction with partially deactivated palladised charcoal (Lindlar's catalyst) gives:

In the reaction sequence $Me_3CCH=CH_2 \xrightarrow{Q} Me_3CCH_2CH_2OH$ and $Me_3CCH=CH_2 \xrightarrow{R} Me_3C-CH(OH)-CH_3$, $Q$ and $R$ are respectively:

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

Compound $X$ on reaction with $O_{3}$ followed by $Zn/H_{2}O$ gives formaldehyde and $2-$methylpropanal as products. The compound $X$ is :

Consider the following reaction sequence:
$2-\text{Methylpropane}$ $\xrightarrow{KMnO_4} X$ $\xrightarrow[358 \ K]{20 \% \ H_3PO_4} Y$ $\xrightarrow[\text{(ii) } Zn \mid H_2O]{\text{(i) } O_3} A + B$
What are $A$ and $B$?