Q4(c). Phenol–water system and the importance of tie lines
Explain the phase diagram of phenol-water system by highlighting the importance of tie lines.
Answer in brief
Phenol and water are partially miscible: two liquid layers inside the dome-shaped solubility curve, one liquid outside it, and an upper critical solution temperature of about 66 °C; a tie line links the two conjugate layers and the lever rule gives their amounts.
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Coversphenol–water systemcritical solution temperaturetie linelever ruleconjugate solutionspartially miscible liquids
All parts of Question 4
- 4(a) E.m.f. of a hydrogen–copper cell at 25 °C10 marks
- 4(b)(i) Thermal conductivity of the gas in an ageing foam10 marks
- 4(b)(ii) van der Waals constants of NO and CCl₄; nearness to ideal behaviour10 marks
- 4(c) Phenol–water system and the importance of tie lines20 marks