What is the freezing point of a 0.5m aqueous solution of C6H12O6?
To determine the freezing point of a 0.5m aqueous solution of C6H12O6 (glucose), we need to use the formula for calculating the freezing point depression.
The freezing point depression (ΔTf) is given by the equation:
ΔTf = Kf * m
Where:
- ΔTf is the change in freezing point
- Kf is the molal freezing point depression constant
- m is the molality of the solution
The molal freezing point depression constant for water is approximately 1.86 °C/m.
Given that the molality (m) of the solution is 0.5m, we can now calculate the freezing point depression:
ΔTf = 1.86 °C/m * 0.5m
ΔTf = 0.93 °C
To find the freezing point of the solution, we subtract the calculated ΔTf from the normal freezing point of water, which is 0 °C:
Freezing point = 0 °C - 0.93 °C
Freezing point ≈ -0.93 °C
Therefore, the freezing point of the 0.5m aqueous solution of C6H12O6 is approximately -0.93 °C.
To determine the freezing point of a solution, we need to use the formula for freezing point depression. This formula states that the freezing point depression (∆Tf) is directly proportional to the molality (m) of the solute. The constant of proportionality is called the cryoscopic constant (Kf), which is specific to each solvent.
To solve this question, we need to know the cryoscopic constant for water (the solvent in this case) and the molality (m) of the aqueous solution of C6H12O6 (glucose).
The cryoscopic constant for water is approximately 1.86 ˚C/m.
First, we need to calculate the molality of the solution by using the formula:
molality (m) = moles of solute / mass of solvent (in kg)
In this case, we have a 0.5m solution, which means there are 0.5 moles of C6H12O6 per kilogram of water.
Next, multiply the molality with the cryoscopic constant (Kf) to find the freezing point depression (∆Tf). This can be calculated by the formula:
∆Tf = m * Kf
Finally, subtract the freezing point depression (∆Tf) from the freezing point of pure water (0 ˚C) to find the freezing point of the solution.
Therefore, you need to know the molality and the cryoscopic constant for water to solve this problem.