$10$ kg of terephthalic acid $($TA$)$ was reacted with an equimolar quantity of ethylene glycol $($EG$)$ by the step$-$growth mechanism in a pilot$-$scale batch reactor.

i$)$ Assuming that TA is $100\%$ pure, calculate the moles of TA charged to the reactor. Ans: $60\mathrm{.}24$ mol

ii$)$ Assuming that EG is $100\%$ pure, calculate the mass $($kg$)$ of EG that must be charged. Ans: $3\mathrm{.}735$ kg

iii$)$ Using the simplified step$-$growth polymerization model, calculate the number average degree of polymerization of the PET polymer formed when the extent of conversion of TA end$-$groups is $0\mathrm{.}995($i$.$e$.,99\mathrm{.}5\%).$ Ans: $200$

iv$)$ Assuming that all water formed during the reaction is removed $($but not any monomer or oligomer$),$ calculate the mass of polymer formed in part $($iii$)$ above.

Answer iv