Which of the following paris will show a negative deviation from Raoult's law?

Options

A. Ethanol and trichloromathane
B. Pyridine and ethanoic acid
C. Heptane and tetrachloromethane
D. both (1) and (2)

Answer

4

Explanation

Both the paris listed in options (1) and (2) exhibit negative deviation on account of relatively strong intermolecular hydrogen bonding:

Other examples of negative devision are: acetone and choroform, toluene and acetic acid
The pair heptane and tetrachloromethane exhibits positive devision on account of weak London or dispersion forces between unlike molecules. Other examples of positive deviation are: acetone and carbon disulphide, carbon tetrachloride and methanol, chloroform and ethanol.