Polymers

Concept:Condensation polymerization between monomers $X$ and $Y$ forms a copolymer $Z$ while eliminating water molecules.Explanation:From the reaction sequence, the molar mass of $X$ is $75\ \mathrm{g/mol}$ and that of $Y$ is $131\ \mathrm{g/mol}$.Mass of $500$ mol of $X$ is $500 \times 75 = 37500\ \mathrm{g}$.Mass of $500$ mol of $Y$ is $500 \times 131 = 65500\ \mathrm{g}$.Total mass of reactants is $37500 + 65500 = 103000\ \mathrm{g}$.Each linkage between $X$ and $Y$ releases $2$ water molecules.For $500$ linkages, the total water lost is $500 \times 2 - 1 = 999$ mol (one less due to polymer chain ends).Molar mass of water is $18\ \mathrm{g/mol}$.Mass of water lost is $999 \times 18 = 17982\ \mathrm{g}$.Mass of polymer $Z$ formed is total mass of reactants minus mass of water lost: $103000 - 17982 = 85018\ \mathrm{g}$.Answer:$85018$