Calculate the freezing point change for a given concentration.

A student prepares a solution by dissolving 2.09 g of para-dichlorobenzene (C6H4Cl2,= 147.0 g/mol) in 50.0 mL of cyclohexane. What is the freezing point (in°C) of the prepared solution? Pure cyclohexane has a freezing point of 6.47°C, a freezing point depression constant of20.0°C/m, and a density of 1.25 g/mL.     Freezing point =______ °C

The freezing point of 59.49 g of a pure solvent is measured to be 44.96 ºC. When 2.18 g of an unknown solute (assume the van 't Hoff factor = 1.0000) is added to the solvent the freezing point is measured to be 42.65 ºC. If the freezing point depression constant of the pure solvent is 7.66 ºC·kg solvent/mol solute calculate the molar mass of the solute. ?=g/mol

A solution of sodium chloride in water has a vapor pressure of 19.6 torr at 25°C. What is the mole fraction of solute particles in this solution? What would be the vapor pressure of this solution at 45°C? The vapor pressure of pure water is 23.8 torr at 25°C and 71.9 torr at 45°C and assume sodium chloride exists as Na+ and Cl- ions in solution?

The normal freezing point of a certain liquid x is -6.20 °C, but when 36. g of iron(III) chloride (FeCl,) are dissolved in 300. g of x the solution freezes at -9.4 °C instead. Use this information to calculate the molal freezing point depression constant K, of x. Round your answer to 2 significant digits. do °C · kg K, = 0- mol ?

Calculate the freezing point of a 14.00?14.00m aqueous solution of methanol. Freezing point constants can be found in the list of colligative constants.   Solvent Formula K f value* (°C/ m ) Normal freezing point ( °C)   K b value (°C/ m ) Normal boiling point ( °C)  water  H 2 O  1.86  0.00  0.512  100.00  benzene  C 6 H 6  5.12  5.49  2.53  80.1  cyclohexane  C 6 H 12  20.8  6.59  2.92  80.7  ethanol  C 2 H 6 O  1.99 –117.3  1.22  78.4  carbon tetrachloride   CCl 4  29.8  –22.9  5.03  76.8  camphor   C 10 H 16 O

A solution is made by adding 0.978 mol sucrose to 250.0 g water. Calculate the boiling point of this solution. The Kb value for water is 0.512 °C/m and the boiling temperature of water is 100.0 °C.

a) What is the freezing point depression caused by adding NaCl to the water? b) The freezing point depression can be calculated using the equation, where DT is the change in freezing point, i is the number of ions in the solution per mole of dissolved NaCl (i = 2), m is the molality of the solution, and Kf  is the molal freezing point constant for water which is 1.86°C/m.  Using this equation and the data recorded above, calculate the molar mass for NaCl. Compare with the accepted value. ---- Here is some data I made up for the problems: Mass NaCl 4 g Mass Water 99.8 g Mass Ice 50 g Mass water+ ice 150 g min. temp -2 C density of water @ 25 C 0.998 g/mL

Determine the freezing point of a solution consisting of 0.350 m KCl in water. The freezing point depression constant, Kf, of water is 1.86 °C/m. Freezing temperature of water is 0.00°C. Assume 100% dissociation of KCl.

Molality   A solution contains 22.5 g of methanol, CH3OH, dissolved in sufficient water to give a total mass of 105.3 g. The molar mass of CH3OH is 32.4 g/mol. What is the molality of the aqueous methanol solution?