If an 0.650 m aqueous solution freezes at –2.00 °C, what is the van't Hoff factor, i, of the solute? Kf values can be found here.
the Kf value is 1.86 °C/m.
I get 2 for the answer but it is wrong. Please help!
delta T = i*Kf*m
2.00 = i*1.86*0.650
i = (2.00/1.86*0.65) = ?
I obtained 1.65 for i.
Oh no, don't worry, I'm here to help you. Let's figure this out together!
To find the van't Hoff factor (i), we can use the equation:
ΔT = i * Kf * m
Where:
- ΔT is the freezing point depression (in this case, -2.00 °C)
- Kf is the freezing point depression constant (1.86 °C/m)
- m is the molality of the solution (we need to find this)
Rearranging the equation, we can solve for i:
i = ΔT / (Kf * m)
To find m, we need to use the equation:
m = moles of solute / kilograms of solvent
Unfortunately, we don't have the moles of solute. So could you please provide the concentration or the mass of the solute in the solution? With that information, we can calculate m and then the van't Hoff factor (i) correctly.
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To find the van't Hoff factor (i) of a solute, you can use the equation:
\(\Delta T = imK_f\)
Where:
- \(\Delta T\) is the freezing point depression
- i is the van't Hoff factor
- m is the molality of the solute (moles of solute divided by mass of solvent in kg)
- K_f is the cryoscopic constant
In this case, you are given the following information:
- \(\Delta T\) = -2.00 °C (since it freezes at -2.00 °C)
- K_f = 1.86 °C/m (given in the question)
To find i, we need to solve for m, which can be done using the molality formula:
\(m = \frac{{moles\, of\, solute}}{{mass\, of\, solvent\, (in\, kg)}}\)
However, to solve this problem, you need the given moles of solute and mass of the solvent. If you have this information, please provide it so I can assist you further.
To determine the van't Hoff factor (i) of the solute, you need to use the formula:
i = ΔTf / (Kf * m)
Where:
ΔTf is the freezing point depression, which is the difference between the freezing point of the pure solvent and the freezing point of the solution.
Kf is the freezing point depression constant (cryoscopic constant) specific to the solvent (given as 1.86 °C/m).
m is the molality of the solution, which is the number of moles of solute per kilogram of solvent.
Given:
ΔTf = -2.00 °C (the freezing point depression)
Kf = 1.86 °C/m (the freezing point depression constant)
Now, we need to calculate the molality (m) of the solution.
To find the molality, we need to know the moles of the solute and the mass of the solvent.
Since the molar mass of water is approximately 18 g/mol, we can calculate the mass of water in the solution using the molality formula:
m = moles of solute / mass of water (in kg)
To calculate the moles of solute, we need to use Avogadro's number and the molarity (M) of the solution.
Since the molarity (M) is not given, we need more information to calculate it. Without the molarity, it's not possible to determine the van't Hoff factor (i) solely based on the given freezing point depression and the freezing point depression constant.
Please provide the molarity (or any additional information) to continue the calculation.