When the vapour pressure of a liquid is equal to its atmospheric pressure, then it (1) freezes (2) evaporates (3) boils (4) does not undergo any change 38. Simple distillation can be best used to separate
(1) A mixture of benzene (boiling point 80o C) and toluene (boiling point 100o C)
(2) A mixture of ether (boiling point 35o C) and toluene (boiling point 110o C)
(3) A mixture of ethanol (boiling point 78o C) and water (boiling point 100oC)
(4) None of these
Answers
1.4 ,2.2, the answer for 1st one is 4 and 2nd is 2
Answer to first question:
Option (3) Boils.
Explanation:
When the vapor pressure of the liquid is same the external atmospheric pressure, then the liquid starts to form bubbles and boil. This occurs at a temperature called boiling point of the liquid.
Answer to second question:
Option (2) A mixture of ether (boiling point 35o C) and toluene (boiling point 110o C).
Explanation:
Simple distillation technique is suitable for separating two liquid mixtures that have difference of at least 25 degrees in their boiling points, so that the process is effective.
Below are the difference in their boiling points, for the given answer options.
(1) 100 - 80 = 20 degrees
(2) 110-35 = 75 degrees
(3) 100-78 = 22 degrees
So, option (2) is the best answer.