A measurement of the depression of the freezing point of the solvent ethylene di
ID: 873765 • Letter: A
Question
A measurement of the depression of the freezing point of the solvent ethylene dibromide C2H4Br2, by the solute benzoic acid, C7H6O2 produces the following results:T(f) for pure ethylene dibromide is 9.79C T(f) for a solution prepared by dissolving 1.023g benzoic acid in 23.482g ethylene dibromide is 7.69C The molal freezing point depression constant for ethylene dibromide is 11.8 C/m
A) assuming that the Van't Hoff factor is one; calculate an experimental value for the molar mass of benzoic acid based upon the measurements above.
B) using your periodic table to calculate the actual molar made of benzoic acid, C7H6O2. Using the theoretical value of molar mass, calculate the Van't Hoff factor based upon the measurements above.
C) what does the calculated value in (b) tell us about the behavior of benzoic acid when dissolved in ethylene dibromide?
A measurement of the depression of the freezing point of the solvent ethylene dibromide C2H4Br2, by the solute benzoic acid, C7H6O2 produces the following results:
T(f) for pure ethylene dibromide is 9.79C T(f) for a solution prepared by dissolving 1.023g benzoic acid in 23.482g ethylene dibromide is 7.69C The molal freezing point depression constant for ethylene dibromide is 11.8 C/m
A) assuming that the Van't Hoff factor is one; calculate an experimental value for the molar mass of benzoic acid based upon the measurements above.
B) using your periodic table to calculate the actual molar made of benzoic acid, C7H6O2. Using the theoretical value of molar mass, calculate the Van't Hoff factor based upon the measurements above.
C) what does the calculated value in (b) tell us about the behavior of benzoic acid when dissolved in ethylene dibromide?
T(f) for pure ethylene dibromide is 9.79C T(f) for a solution prepared by dissolving 1.023g benzoic acid in 23.482g ethylene dibromide is 7.69C The molal freezing point depression constant for ethylene dibromide is 11.8 C/m
A) assuming that the Van't Hoff factor is one; calculate an experimental value for the molar mass of benzoic acid based upon the measurements above.
B) using your periodic table to calculate the actual molar made of benzoic acid, C7H6O2. Using the theoretical value of molar mass, calculate the Van't Hoff factor based upon the measurements above.
C) what does the calculated value in (b) tell us about the behavior of benzoic acid when dissolved in ethylene dibromide?
Explanation / Answer
A measurement of the depression of the freezing point of the solvent ethylene dibromide C2H4Br2, by the solute benzoic acid, C7H6O2 produces the following results:
T(f) for pure ethylene dibromide is 9.79C
T(f) for a solution prepared by dissolving 1.023g benzoic acid in 23.482g ethylene dibromide is 7.69C
The molal freezing point depression constant for ethylene dibromide is 11.8 C/m
Solution :
Depression in freezing point is colligative property.
The mathematical expression for it is as follow
Delta Tf = i Kf * m
Here DetlaTf is depression in freezing point. Kf is freezing point constant. m is molal concentration (molality)
Lets calculate molality of benzoic acid in ethylene dibromide
Delta Tf = Freezing point of pure solvent
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.