Problem 42 - Chemistry Central Science

Question

Write a chemical equation for formation of a polymer via a condensation reaction from the monomers succinic acid \(\left(\mathrm{HOOCCH}_{2} \mathrm{CH}_{2} \mathrm{COOH}\right)\) and ethylenediamine \(\left(\mathrm{H}_{2} \mathrm{NCH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}\right)\).

Step-by-Step Solution

Answer

The chemical equation for the formation of the polymer from succinic acid and ethylenediamine is: \[ n\left(\mathrm{HOOCCH}_{2}\mathrm{CH}_{2}\mathrm{COOH}\right) + n\left(\mathrm{H}_{2}\mathrm{NCH}_{2}\mathrm{CH}_{2}\mathrm{NH}_{2}\right) \rightarrow \left[\mathrm{OCOCH}_{2}\mathrm{CH}_{2}\mathrm{CONHCH}_{2}\mathrm{CH}_{2}\mathrm{NH}\right]_{n} + n\mathrm{H}_{2}\mathrm{O} \] The polymer formed is a polyamide with an amide linkage between the succinic acid and ethylenediamine monomers.

Step 1: Identify functional groups in each monomer

Succinic acid is a dicarboxylic acid with two carboxyl groups (COOH), while ethylenediamine is a diamine with two primary amine groups (NH₂).

Step 2: Write the chemical equation for monomer reaction

In the condensation reaction, the carboxyl group of succinic acid will react with the amine group of ethylenediamine to form an amide linkage (-CONH-), eliminating a molecule of water in the process. The general reaction is as follows: \[ \mathrm{HOOCCH}_{2}\mathrm{CH}_{2}\mathrm{COOH} + \mathrm{H}_{2}\mathrm{NCH}_{2}\mathrm{CH}_{2}\mathrm{NH}_{2} \rightarrow \mathrm{HOOCCH}_{2}\mathrm{CH}_{2}\mathrm{CONHCH}_{2}\mathrm{CH}_{2}\mathrm{NH}_{2} + \mathrm{H}_{2}\mathrm{O} \] This reaction forms a single unit of the polymer, which can then react with more succinic acid and ethylenediamine molecules to continue the polymerization process.

Step 3: Write the chemical equation for polymer formation

The formation of the polymer can be represented using brackets and an 'n' to indicate the repeated units in the polymer chain. The chemical equation for the formation of the polymer from succinic acid and ethylenediamine is: \[ n\left(\mathrm{HOOCCH}_{2}\mathrm{CH}_{2}\mathrm{COOH}\right) + n\left(\mathrm{H}_{2}\mathrm{NCH}_{2}\mathrm{CH}_{2}\mathrm{NH}_{2}\right) \rightarrow \left[\mathrm{OCOCH}_{2}\mathrm{CH}_{2}\mathrm{CONHCH}_{2}\mathrm{CH}_{2}\mathrm{NH}\right]_{n} + n\mathrm{H}_{2}\mathrm{O} \] The final polymer product has an amide linkage between the succinic acid and ethylenediamine monomers, forming a polyamide.