Q12.114P - Chemistry: Molecular Nature Of Matter And Change

Question

The monomer of poly (vinyl chloride) has the formula ${\mathbf{C}}_2{\mathbf{H}}_3\mathbf{Cl}$ . If there are 1565 repeat units in a single chain of the polymer, what is the molecular mass (in amu) of that chain?

Step-by-Step Solution

Answer

The molar mass of the molecule is 62.5 g/mole and the molar mass of the polymer is 95,312.5.

Step 1: Definition

Polymer may be defined as the complex molecule which is formed by the addition or condensation of the small units called monomer. Polymer mass is the mass of the complex molecule which contained many types of similar or different monomers. The mass of the polymer is very high.

 

Polymer mass can be calculated by the formula:

 

$\begin{array}{c}{\mathbf{{\rm M}}}_{\mathrm{polymer}}\mathbf{=}{\mathbf{M}}_{\mathrm{repeat}}\mathbf{\times }\mathbf{n}\\ {\mathbf{{\rm M}}}_{\mathrm{polymer}}\mathbf{=}\mathrm{Polymer}\mathrm{mass}, \\ {\mathbf{M}}_{\mathrm{repeat}} =\mathrm{Repeating}\mathrm{the}\mathrm{unit}’\mathrm{s}\mathrm{massn} \\ \mathrm{n}=\mathrm{degree}\mathrm{of}\mathrm{polymerization}.\end{array}$

Step 2: Explanation

Molar Mass of the molecule  ${\mathbf{C}}_2{\mathbf{H}}_3\mathbf{Cl}$ :

 $\begin{array}{c}\mathrm{Molar} \mathrm{Mass} \mathrm{of} \mathrm{molecule}=2\times \mathrm{C}+3\times \mathrm{H}+1\times \mathrm{Cl}\\ \mathrm{Molar} \mathrm{Mass} \mathrm{of} \mathrm{molecule}=2\times 12+3\times 1+1\times 35.5\\ \mathrm{Molar} \mathrm{Mass} \mathrm{of} \mathrm{molecule}=62.5\mathrm{g}/\mathrm{mole}\end{array}$

 

 

The repeating units of the molecule  ${\mathbf{C}}_2{\mathbf{H}}_3\mathbf{Cl}$:

 $\begin{array}{l}{\mathrm{{\rm M}}}_{\mathrm{polymer}}={\mathrm{M}}_{\mathrm{repeat}}\times \mathrm{n}\\ {\mathrm{{\rm M}}}_{\mathrm{polymer}}=62.5\mathrm{g}/\mathrm{mole}\times 1525\\ {\mathrm{{\rm M}}}_{\mathrm{polymer}}=95,312.5\end{array}$