How do you calculating freezing point from molality?
One of the colligative properties of solutions is freezing-point depression.
This phenomenon helps explain why adding salt to an icy path melts the ice, or why seawater doesn't freeze at the normal freezing point of
The equation for freezing point depression is given by
#ulbar(|stackrel(" ")(" "DeltaT_f = imK_f" ")|)#
where
-
#DeltaT_f# represents the change in freezing point of the solution -
#i# is called the van't Hoff factor, which is essentially the number of dissolved particles per unit of solute (for example,#i = 3# for calcium chloride, because there is#1# #"Ca"^(2+) + 2# #"Cl"^(-)# ). -
#m# is the molality of the solution, the number of moles of solute dissolved per kilogram of solvent:
#"molality" = "mol solute"/"kg solvent"#
#K_f# is the molal freezing-point depression constant for the solvent, which the following table lists some values for certain solvents:(the far-right column shows the
#K_f# )Once you've calculated the change in freezing point, to find the new freezing point, you subtract the
#DeltaT_f# quantity from the normal freezing point of the solvent:#ul("new f.p." = "normal f.p." - DeltaT_f# (I'd like to point out that depending on how you're taught, the
#DeltaT_f# quantity may be negative (possibly because the constant#K_f# was negative). Just know that the magnitude of the#DeltaT_f# quantity (regardless of sign) represents by how much the freezing point is lowered.)
By signing up, you agree to our Terms of Service and Privacy Policy
To calculate the freezing point depression from molality, you can use the formula:
ΔTf = Kf * m
Where: ΔTf = freezing point depression (in °C) Kf = cryoscopic constant (specific to the solvent, typically given in units of °C kg/mol or °C/m) m = molality of the solute (moles of solute per kilogram of solvent)
Multiply the cryoscopic constant (Kf) by the molality (m) of the solute to find the freezing point depression (ΔTf).
By signing up, you agree to our Terms of Service and Privacy Policy
When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
- How many grams of nitric acid are present in 250.0 mL of 6.70 M acid solution?
- How does a suspension differ from solution?
- Will magnesium fluoride be more soluble in acidic solution?
- Can you solve this? The concentration of the #Zn^(2+)# ions in blood serum is 1.2 ppm. Express this amount in terms of millimole/L and milliequivalent/L.
- I want to increase the NO3 concentration in a 40 Liters tank using Ca(NO3)2.4H2O. The concentration of the CaNO3 solution is 500g/L. How much solution do I need to add increase the concentration by 2ppm? Thanks for helping out!

- 98% accuracy study help
- Covers math, physics, chemistry, biology, and more
- Step-by-step, in-depth guides
- Readily available 24/7