Answer:
the freezing point of the 5.6 molal solution of ethylene glycol in ethanol is -125.744 °C
Step-by-step explanation:
To calculate the freezing point depression of a solution, we can use the formula:
ΔTf = Kf * molality
where:
ΔTf is the freezing point depression
Kf is the freezing point depression constant for the solvent (in this case, ethanol)
molality is the number of moles of solute per kilogram of solvent.
The freezing point depression constant for ethanol is 1.99 °C/m.
We are given that the solution is 5.6 molal, which means there are 5.6 moles of ethylene glycol per kilogram of ethanol.
So, we can calculate the freezing point depression as:
ΔTf = 1.99 °C/m * 5.6 mol/kg = 11.144 °C
The freezing point depression is 11.144 °C.
To find the freezing point of the solution, we can subtract this value from the freezing point of pure ethanol, which is -114.6 °C.
Freezing point of solution = -114.6 °C - 11.144 °C = -125.744 °C
Therefore, the freezing point of the 5.6 molal solution of ethylene glycol in ethanol is -125.744 °C.