A solute depresses the freezing point of a solution because the solute can not fit perfectly into the crystal lattice of the solid solvent. The normal crystal lattice is the lowest energy arrangement of the molecules or ions of the solid solvent. Therefore, the disordered lattice of a solvent freezing in the presence of a solute has at least slightly higher energy than the lattice of a solid pure solvent and requires at least a slightly lower temperature to solidify.
because the solute disrupts crystal formation by the solvent
A solute depresses the freezing point because the solute disrupts crystal formation. If crystals cannot form, the freezing point cannot be attained.
Examples are chlorides of Na, K and Ca.
f.p depression = (freezing point of pure solvent)-(freezing point of solution) -------> 178.4-166.2=12.2
Higher boiling point and a lower freezing point. These are called colligative properties. When a solute is put into solution with the solvent, there is a change in the vapor pressure, osmotic pressure, elevation of the boiling point, and depression of the freezing point.
They usually lower freezing points, think antifreeze. And salt water freezes at a lower temp than fresh, that is why they put salt on ice. And they raise boiling points, think salt in water when making spaghetti. Or, again antifreeze.
Any solute lowers the freezing point; there's nothing special about NaCl. One way to think about this is that the solute molecules "get in the way" of the freezing process: they don't fit into the regular crystalline lattice of the solid, which makes it harder to go from a liquid to a solid, which means the freezing point goes down.
To solve freezing point depression problems, you need to know the following things:-- the identity of the solute (the thing you are adding to the liquid)-- the identity of the solvent (the liquid)-- whether the solute is molecular or ionic, and if ionic, how many ions it forms-- the amount of solute (in grams or moles)-- the amount of solvent (in kilograms)-- the value of Kf of the solvent (for water, it is -1.858 K·kg/mol (or -1.858 °C molal-1)Then you use the following equation:∆T = i * Kf * mwhere ∆T is the change in the freezing point, "i" is the number of molecules or ions formed upon addition to the solvent, Kf is the freezing point depression constant, and "m" is the molality of the solution.The Kf of water for a freezing point depression is known and is equal to -1.858 °C·kg/mol (or -1.858 °C molal-1)The value of "i" has to do with what you add to the water. If you added sugar, a molecular compound the value of "i" is 1.0. If you add a ionic compound like NaCl, the value of "i" is 2.0 because for every 1 molecule of NaCl, you make 2 ions: one Na+ and one Cl- in water. For MgCl2, the value of "i" is thus 3.0 (for each MgCl2 you get one Mg2+ and two Cl- ions, so a total of 3 ions).To find "m," the molality of a solution you need to know the number of moles of solute and the number of kilograms of solvent (m = moles/kg). If you are given the number of grams of solute, the number of moles is found from the mass and the molar mass of the solute.grams of solute ÷ molar mass of solute = moles of soluteTo find the molality, just divide the moles of solute by the kilograms of solvent moles of solute ÷ kilograms solvent = molality Note: If you are given the volume of the solvent instead of the mass, use the density of the solvent to convert -- the density of water is 1 kilogram per liter)Liters of solvent * density of solvent = kilograms of solventNow just plug all the numbers into the equation at the top of the answer!
The freezing point is lowered.
When any solute is dissolved into a solvent, the freezing point will always go down.
When a solute is dissolved into water the freezing point will lower. In other words, if you want to freeze a solution of water and some solute, you will have to cool it beyond the freezing point of pure water.
Yes, it is possible if the solution contain solutes.
the temperature at which the solution freezes is lowered.
the temperature at which the solution freezes is lowered.
Freezing point depression. When a solution is formed the molecules of the solute prevent the solution from freezing at its normal freezing point, it must be colder.
1. Vapor pressure lowering: the decrease in vapor pressure with increasing the number of solute molecules in solution. 2. Boiling point elevation: the increase in boiling point with increasing number of solute molecules in solution. 3. Freezing point depression: the decrease in freezing point with increasing number of solute molecules in solution. 4. Osmotic pressure
The freezing point is lowered slightly as some energy is absorbed by the impurities.
boiling point is increased and freezing point is decreased
This depends on: molality of the solute, dissociation of the solute, cryoscopic constant of the solvent.
f.p depression = (freezing point of pure solvent)-(freezing point of solution) -------> 178.4-166.2=12.2