MEDIUMMCQ SINGLEIChO (Chemistry Olympiad)Physical ChemistrySolutionsPrevious Year Questions
Which one of the following statements given below concerning properties of solution, describes a colligative effect? (AllMS 2013)
A.Boiling point of pure water decreases by the
B.Vapour pressure of pure water decreases by the
C.Vapour pressure of pure benzene decreases by the✓ Correct
D.Boiling point of pure benzene increases by the
Explanation
The colligative properties are the properties of dilute solution of non-volatile solutes whose value depend on concentration of solute particles in the solution. Naphthalene is a non-volatile solid whereas, all other solutes are volatile. Hence, addition of naphthalene in benzene decreases the vapour pressure of benzene.