I don't know how to answer this. An aqueous solution of glucose has a freezing point of -0.37. What is the concentration of the solution?
Decrease in freezing temperature caused by glucose= 0°C-(-0.37)= 0.37°C
∆T_f= K_f x m
0.37°C= 1.86°C x m
m= 0.37°C/ 1.86°C
= 0.2 mole of glucose in 1kg water
To find the concentration of the solution, we need to know the freezing point depression constant of water (Kf) and the molal freezing point depression constant (ΔTf). The ΔTf is the difference between the freezing point of the pure solvent (water) and the freezing point of the solution.
The formula for ΔTf is given by:
ΔTf = Kf * m
where ΔTf is the freezing point depression, Kf is the freezing point depression constant, and m is the molality of the solution (moles of solute per kilogram of solvent).
Given that the freezing point depression (ΔTf) is -0.37°C and the freezing point depression constant (Kf) for water is 1.86°C/m, we can rearrange the formula to solve for the molality (m):
m = ΔTf / Kf
m = -0.37°C / 1.86°C/m
m = -0.198
The concentration of the solution is -0.198 mol/kg.
To determine the concentration of the aqueous solution of glucose, we need to use the concept of freezing point depression. The freezing point depression is defined as the difference between the freezing point of the pure solvent and the freezing point of the solution.
The equation that relates freezing point depression with concentration is:
ΔTf = Kf * m
Where:
ΔTf is the freezing point depression,
Kf is the cryoscopic constant (a property of the solvent),
m is the molality of the solute (moles of solute per kilogram of solvent).
In this case, the freezing point depression (ΔTf) is given as -0.37 (the temperature difference between the freezing point of pure water and the freezing point of the solution).
The cryoscopic constant for water (Kf) is approximately 1.86 °C/m.
To find the molality (m), we use the following formula:
m = (ΔTf) / (Kf)
Plugging in the given values:
m = -0.37 / 1.86
m ≈ -0.198
Molality cannot be negative; therefore, there is an error in the given data or calculation. Please make sure the values are correct, as a negative molality is not possible.
You need to understand colligative properties.
freezing pt depression=-molality*.52
solve for the concentration in molalities.