A mixture of methanol (boiling point 65 ∘C65\,^\circ\mathrm{C}65∘C), ethanol (boiling point 78 ∘C78\,^\circ\mathrm{C}78∘C) and water (boiling point 100 ∘C100\,^\circ\mathrm{C}100∘C) is separated by fractional distillation. After some time, the thermometer at the top of the column reads 78 ∘C78\,^\circ\mathrm{C}78∘C for several minutes. Which liquid is condensing in the condenser at this time, and why?
methanol, because it has the lowest boiling point of the three liquids
water, because the liquid in the flask is now hotter than 78 ∘C78\,^\circ\mathrm{C}78∘C
all three liquids, because all three evaporate from the hot liquid in the flask
ethanol, because methanol has distilled over and water condenses lower down
107 exam-style questions on Edexcel GCSE Chemistry 3.2 Methods of separating and purifying substances, covering 3.2.1 Pure substances and mixtures, 3.2.2 Techniques for separating mixtures, 3.2.3 Paper chromatography and Rf values, and 3.2.4 Making water potable. Each one has a worked solution and a mark scheme showing where the marks go.