Waec Model Questions Vol1 2017 Chemistry Question 25
Practice objective / multiple choice question 25 from the 2017 Waec Model Questions Vol1 Chemistry examination.
A sample of polyethylene terephthalate (PET) is prepared by condensation polymerisation of ethylene glycol (C₂H₆O₂, M=62.07 g mol⁻¹) and terephthalic acid (C₈H₆O₄, M=166.13 g mol⁻¹). The polymer contains 0.5 % by mass of residual -OH end groups (from ethylene glycol) and 0.3 % by mass of residual -COOH end groups (from terephthalic acid). Assuming each polymer chain has exactly one -OH end and one -COOH end, determine the number‑average degree of polymerisation (DPₙ) of the PET sample. (M_{repeat}=192.17 g mol⁻¹, M_{‑OH}=45.07 g mol⁻¹, M_{‑COOH}=45.02 g mol⁻¹)
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About This Question
This is Waec Model Questions Vol1 2017 Chemistry Question 25. It is one of the objective questions from the 2017 Waec Model Questions Vol1 Chemistry examination.
Difficulty level: Hard .
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