Phosgene is formed slowly from which one of the following on exposure to air and sunlight?

The rate of $S_{N}2$ reaction is maximum when the solvent is

Iodoethane reacts with sodium in the presence of dry ether. The product is

How many minimum numbers of $C$-atom containing monohaloalkane shows optical isomerism?

$A$ dihalogen derivative $X$ of a three-carbon hydrocarbon reacts with alcoholic $KOH$ to give another hydrocarbon,which gives a red precipitate with ammoniacal $Cu_2Cl_2$. Reaction of $X$ with aqueous $KOH$ gives an aldehyde. The compound $X$ is .......

In the following reaction $C_6H_5CH_2Br \xrightarrow{1. Mg, \text{ ether } \atop 2. H_3O^{+}} X$,the product $X$ is