The freezing-point depression is -0.930 Celsius degree. Determine the molality of the solution of an unknown nonelectrolyte in water.
Please help!! I do not understand this problem!
Just plug into the equation.
delta T = Kf*m
delta T = 0.930
Kf = 1.86, a constant for water.
m is molality. That's the only unknown. Solve for that.
To determine the molality of the solution, we need to use the formula for freezing-point depression. The formula is as follows:
∆Tf = Kf * m
Where:
∆Tf is the freezing-point depression
Kf is the cryoscopic constant for the solvent (in this case, water)
m is the molality of the solution
In this problem, the freezing-point depression (∆Tf) is given as -0.930 Celsius degree. We need to find the molality (m) of the solution. Water has a cryoscopic constant (Kf) of 1.86 °C/m.
We can rearrange the formula to solve for molality (m):
m = ∆Tf / Kf
Now, substitute the given values into the equation:
m = -0.930 °C / (1.86 °C/m)
m = -0.930 °C / 1.86 °C/m
m ≈ -0.5 m
Therefore, the molality of the solution of an unknown nonelectrolyte in water is approximately -0.5 m.
To determine the molality of the solution, we can use the formula:
ΔT = Kf * m
Where:
ΔT = freezing-point depression
Kf = cryoscopic constant of water (which is 1.86 °C/m for water)
m = molality of the solution
In this case, the freezing-point depression is given as -0.930 °C. We can substitute these values into the equation to solve for m.
-0.930 °C = (1.86 °C/m) * m
Now, let's solve for m:
-0.930 °C = 1.86 °C * (m/m)
Since m/m is just equal to 1, we can simplify the equation to:
-0.930 °C = 1.86 °C * 1
Now, divide both sides of the equation by 1.86 °C to isolate m:
-0.930 °C / 1.86 °C = m
Simplifying further:
m = -0.5 mol/kg
The molality (m) of the solution is -0.5 mol/kg.
Keep in mind that molality is expressed in moles of solute per kilogram of solvent. In this case, since the given compound is an unknown nonelectrolyte in water, the solvent is water.