Question

What product will we get from the reaction
${C_6}{H_5}CHO + C{H_3}C{H_2}OH\left( {reagentHCl} \right) \to ?$
$C{H_3}C{H_2}C{(Cl)_2}CHO + {H_2}O\left( {reagent{H^ + }} \right) \to$ ?

Answer 1

Alcohols are the chemical compounds containing $- OH$ group and aldehydes belong to carbonyl compounds. When alcohols and aldehydes are reacted in the presence of strong acids like hydrochloric acid hemi acetals will be formed. Aldehydes when treated with water from hydrates.

Complete answer:
Chemical compounds are classified into functional groups based on the groups present in them. Alcohols are the chemical compounds consisting of the $- OH$ group. These are also known as hydroxyl compounds. Carbonyl compounds are the chemical compounds consisting of $C = O$ group. Aldehydes and ketones belong to carbonyl compounds.
Given molecules are benzaldehyde which is an aldehyde and ethanol which is an alcohol, when treated with reagents like hydrochloric acid which is a strong acid, the ethoxy group will attack on the carbonyl carbon to form a compound known as hemiacetal.
The chemical reaction involved will be as follows:
${C_6}{H_5}CHO + C{H_3}C{H_2}OH\left( {reagentHCl} \right) \to {C_6}{H_5}CH\left( {OH} \right)OC{H_2}C{H_3}$
Given molecules are $2,2$ dichloro butanal which is an aldehyde, when treated with a water molecule, the water molecule attacks on carbonyl carbon to form a compound known as hydrate. This reaction can be done in the presence of acid which acts as a catalyst.
The chemical reaction involved will be as follows:
$C{H_3}C{H_2}C{(Cl)_2}CHO + {H_2}O\left( {reagent{H^ + }} \right) \to C{H_3}C{H_2}C{(Cl)_2}CH{\left( {OH} \right)_2}$

Note:
When aldehyde is treated with a molecule of ethanol in presence of strong acid hemi acetals will be formed. Whereas when ketones are treated with a molecule of ethanol in presence of strong acid acetals will be formed. Hemiacetals have one hydroxyl group and one alkoxy group at carbonyl carbon, whereas acetals have two alkoxy groups at carbonyl carbon.