ethanol (boiling point 78) and water can be separated using apparatus shown in figure 3. when the mixture of ethanol and water is heated both liquids vaporise. explain why the liquids then seperate. (3 marks)

Answer 1

The liquids separate because ethanol has a lower boiling point than water. When the mixture is heated, ethanol vaporizes first since it reaches its boiling point of 78 degree Celsius before water which has a boiling point of 100 degree Celsius. The gaseous ethanol rises up and enters the condenser where it is quickly cooled and condenses back into a liquid, which is collected separately from the water. The water continues to vaporize until it reaches its boiling point and is also collected separately. Therefore, the difference in boiling points of ethanol and water is exploited to separate them.