The reaction of lithium di-$3-$pentylcuprate with ethyl bromide yields an alkane with the molecular formula $C_7H_{16}$. What is the structure of the alkane?

Identify $D$ and $E$ in the following reaction: $CH_3-CH(CH_3)-CH(CH_3)-CH_3 \xleftarrow[ether]{Na} R'-Br$ $\xrightarrow{Mg} D$ $\xrightarrow{H_2O} E$

The number of secondary hydrogens in $2, 2-$dimethylbutane is

Choose the chain terminating step.
$(1)$ $H_2 \to H^{\bullet} + H^{\bullet}$
$(2)$ $Br_2 \to Br^{\bullet} + Br^{\bullet}$
$(3)$ $Br^{\bullet} + HBr \to H^{\bullet} + Br_2$
$(4)$ $H^{\bullet} + Br_2 \to HBr + Br^{\bullet}$
$(5)$ $Br^{\bullet} + Br^{\bullet} \to Br_2$

$CH_3-CH_2-COO^{-} Na^{+} \xrightarrow[\Delta]{NaOH + ?} CH_3-CH_3 + Na_2CO_3$. Consider the above reaction and identify the missing reagent/chemical.

Consider the isomers of the hydrocarbon with molecular formula $C_5H_{10}$. These isomers do not decolourise $KMnO_4$ solution. These isomers are subjected to chlorination with chlorine in the presence of light to give monochloro compounds. The total number of monochloro compounds (structural isomers only) formed from all these isomers is . . . . . . .