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 a objective / multiple choice question from the 2017 Waec Model Questions Vol1 Chemistry examination.
Difficulty level: Hard .
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