What is the KF for stearic acid?
4.5 °C kg /
A researcher takes 5.00 g of tridecanoic acid (MW = 214.34 g / mole) and dissolves it in 20.0g of stearic acid (kf = 4.5 °C kg / mole).
What is freezing point of stearic acid?
69.3 °C
Stearic acid/Melting point
Is freezing point depression constant?
It is a constant that is equal to the change in the freezing point for a 1-molal solution of a nonvolatile molecular solute. For water, the value of Kf is −1.86oC/m. Every solvent has a unique molal freezing-point depression constant.
How do you find the freezing point depression constant?
Divide the freezing point depression by the molal concentration so you have: Kf = delta Tf / cm. Insert the values for delta Tf and cm. For instance, if you have a solution with a molality of 0.455 which freezes at 3.17 degrees Celsius, then Kf would equal 3.17 divided by 0.455 or 6.96 degrees Celsius.
Is melting point the same as freezing point?
Freezing occurs at the same temperature as melting, hence, the melting point and freezing point of a substance are the same temperature. The melting/freezing point of a substance is defined as the temperature above which, the substance is liquid and below which, it is solid.
What is melting point and freezing point?
Definition. Freezing point is the temperature at which a liquid becomes a solid at normal atmospheric pressure. Alternatively, a melting point is the temperature at which a solid becomes a liquid at normal atmospheric pressure.
What is freezing point depression used for?
The freezing-point depression prevents radiators from freezing in winter. Road salting takes advantage of this effect to lower the freezing point of the ice it is placed on. Lowering the freezing point allows the street ice to melt at lower temperatures, preventing the accumulation of dangerous, slippery ice.
What is an example of freezing point depression?
Freezing Point Depression Examples For example, the freezing point of seawater is lower than that of pure water. The freezing point of water to which antifreeze has been added is lower than that of pure water. Vodka may be considered a solution of ethanol (solute) in water (solvent).