Question

Ethyl hydrogen sulphate is obtained by the reaction of $H_{2}S{O}_4$ on
(a) Ethylene
(b) Ethane
(c) Ethyl chloride
(d) Ethanol

Answer 1

Hint: While attempting this question, we need to check how sulphuric acid reacts with each of these compounds. Ethylene, also known as Ethene, is an alkene with two carbon atoms and has the molecular formula $C{H}_2=C{H}_2.$ Ethane is an alkane with two carbon atoms and has the molecular formula $C{H}_{3}C{H}_3.$ Ethyl chloride has the molecular formula $C{H}_{3}C{H}_{2}Cl,$ while Ethanol is an alcohol with formula $C{H}_{3}C{H}_{2}OH.$

Complete answer:
Ethyl hydrogen sulphate, which is the IUPAC name for ethyl sulphate, also known as sulphonic acid, is an organic compound. It is used as an intermediate while producing ethanol from ethylene. The molecular formula of ethyl hydrogen sulphate is $C{H}_3-C{H}_2-O-S{O}_{3}H.$
The production of ethyl hydrogen sulphate is by reacting ethanol with sulphuric acid under ${140}^{\circ }C.$ The chemical equation of the reaction is as follows:
 $$\begin{gathered} C{H}_{3}C{H}_{2}OH+H_{2}S{O}_4\to C{H}_3-C{H}_2-O-S{O}_{3}H+H_{2}O \\ \text{ Ethanol Ethyl hydrogen sulphate} \end{gathered}$$
Here, ethanol loses a hydrogen atom and forms the ethyl ester of sulphuric acid along with which a molecule of water is formed by reacting with sulphuric acid.
Hence, the required answer is (d).

Note:
It was mentioned earlier that ethanol can be prepared from ethylene. In this process, ethylene reacts with sulphuric acid, which gives ethyl hydrogen sulphate which on hydration gives ethanol. This method is usually avoided and is replaced by direct hydration of ethene. It is important to note that the sulphuric acid must be added slowly and dropwise in this reaction, or the mixture should be cooled in intervals, as the reaction is highly exothermic.