Question

Write the name and molecular formula of an organic compound having its name suffixed with 'ol' and having two carbon atoms in the molecular. With the help of a balanced chemical equation indicate what happens when it is heated with excess conc. ${{H}_{2}}S{{O}_{4}}$.

Answer 1

This question is based on the nomenclature of the functional group attached to an organic molecule. A functional group can be defined as the moiety or substance that affects and changes the characteristics of the chemical reaction of a molecule.

Complete answer:
The functional groups which have the suffix 'ol' are alcohols.
The chemical formula of the alcohol functional group is R-OH. (where R is an alkyl group and -OH is the hydroxyl group)
Two carbon-membered hydrocarbons are called ethane and its hydrocarbon radical is known as ethyl.
So, two-carbon membered alcohol will be called ethanol ($C{{H}_{3}}COOH$).
Ethyl alcohol or drinking alcohol can also be used to describe ethanol.
Now, when ethanol is reacted with an excess of heated concentrated sulfuric acid (${{H}_{2}}S{{O}_{4}}$), which acts as a dehydrating agent and at a temperature of around 413K, the alcohol dehydrates and diethyl ether (${{C}_{2}}{{H}_{5}}O{{C}_{2}}{{H}_{5}}$) is formed.
$2C{{H}_{3}}C{{H}_{2}}OH\xrightarrow[413K]{+(conc.){{H}_{2}}S{{O}_{4}}(excess)}{{C}_{2}}{{H}_{5}}-O-{{C}_{2}}{{H}_{5}}+{{H}_{2}}O$
In this reaction, ${{S}_{N}}2$ a nucleophilic substitution reaction mechanism is followed.

Additional Information:
If concentrated sulfuric acid is not taken in excess and its temperature is of around 443K, dehydration takes place to form ethene gas ($C{{H}_{2}}=C{{H}_{2}}$).
$C{{H}_{3}}C{{H}_{2}}OH\xrightarrow[443K]{+(conc.){{H}_{2}}S{{O}_{4}}}C{{H}_{2}}=C{{H}_{2}}(g)+{{H}_{2}}O$
In this reaction, the E2 bimolecular elimination reaction mechanism is followed.

Note:
This particular question can be confusing as the reaction of concentrated sulfuric acid (${{H}_{2}}S{{O}_{4}}$) with ethanol follows two reactions and gives two different products. The factors influencing the dehydration products and the reaction followed are
- The temperature of the system.
- The amount of dehydrating agent concentrated sulfuric acid (${{H}_{2}}S{{O}_{4}}$) used.