Question

the normal boiling point of diethyl ether is 34.5. a solution containing a nonvolatile solute dissolved in diethyl ether has a vapor pressure of 698 torr at 34.5.what is the mole fraction of diethyl in this solution

Answer 1

Answer:

The mole fraction of diethyl ether in the solution is 0.918.

Explanation:

Given data:  

Normal boiling point of diethyl ether is 34.5 °C.

Vapour pressure of the non-volatile solute at 34.5 °C i.e., "Psolution" is 698 torr.

To find: Mole fraction of the solvent diethyl ether i.e., “χsolvent” in the solution.

As the vapour pressure of the system is equal to the room temperature pressure i.e., 760 mmhg. We have the normal boiling temperature of diethyl ether as 34.5°C, therefore the vapour pressure of diethyl ether i.e., “P°solvent " will be 760 torr [ 1 mmHg = 1 torr].

According to Raoult’s Law, we have

Psolution = (χsolvent) * (P°solvent )

Or, 698 = χsolvent * 760

Or, χsolvent = 698 / 760 = 0.918