Equilibrium constant
The Equilibrium Constant of an
Ester Hydrolysis Reaction
CHM 152LL Section 33263
March 28, 2014
John Weide
Abstract:
The purpose if this experiment is to determine the equilibrium constant of an unknown alcohol. In this experiment unknown alcohol number three and unknown ester number three were used. The equilibrium constant was found by titrating a series of reactions containing H2O, HCl, and the unknown ester with only the last solution containing the unknown alcohol. Equilibrium constants can be easily found once the concentrations of all reactants are known using Keq= [ acid][alcohol]/[ester][water].
Procedure:
Part A: Prepare six bottles with the following volumes in each:
Bottle # 3M HCl in mL H2O in mL Ester in mL Alcohol in mL
1 5 5 0 0
1/A 5 5 0 0
2 5 0 5 0
3 5 1 4 0
4 5 3 2 0
5 5 2 2 1
Once the bottles are prepared shake the solutions thoroughly and let sit for two weeks shaking periodically.
Part B: Prepare a NaOH solution by dissolving 14g of NaOH pellets in 500mL of deionized water.
Next standardize the NaOH solution by picking weights of KHP ranging from 2g to 5g and add 50mL of water to the KHP and three drops phenolphthalein indicator. Titrate the solution to a pale pink endpoint. Three titrations should be done with varying KHP weights so as to get an accurate molarity for the NaOH solution.
Part C: After two weeks have passed titrate the reaction mixtures by transferring the contents from the bottles into an Erlenmeyer flask, rinsing any remaining solution into the flask with deionized water and adding three drops of phenolphthalein indicator. Titrate the solution to a pale pink end point.
Data:
Part A: Unknown alcohol #3 density 0.7914 g/mL molar mass 32.04 g/mol Unknown ester #3 density 0.9342 g/ mL molar mass 74.08 g/mol HCl 0.3 molarity Mass bottle
Bottle # Initial weight Weight plus HCl Final weight
1 17.6670g 23.4250g 28.7826g
1/A 19.9177g
Ester Hydrolysis Reaction
CHM 152LL Section 33263
March 28, 2014
John Weide
Abstract:
The purpose if this experiment is to determine the equilibrium constant of an unknown alcohol. In this experiment unknown alcohol number three and unknown ester number three were used. The equilibrium constant was found by titrating a series of reactions containing H2O, HCl, and the unknown ester with only the last solution containing the unknown alcohol. Equilibrium constants can be easily found once the concentrations of all reactants are known using Keq= [ acid][alcohol]/[ester][water].
Procedure:
Part A: Prepare six bottles with the following volumes in each:
Bottle # 3M HCl in mL H2O in mL Ester in mL Alcohol in mL
1 5 5 0 0
1/A 5 5 0 0
2 5 0 5 0
3 5 1 4 0
4 5 3 2 0
5 5 2 2 1
Once the bottles are prepared shake the solutions thoroughly and let sit for two weeks shaking periodically.
Part B: Prepare a NaOH solution by dissolving 14g of NaOH pellets in 500mL of deionized water.
Next standardize the NaOH solution by picking weights of KHP ranging from 2g to 5g and add 50mL of water to the KHP and three drops phenolphthalein indicator. Titrate the solution to a pale pink endpoint. Three titrations should be done with varying KHP weights so as to get an accurate molarity for the NaOH solution.
Part C: After two weeks have passed titrate the reaction mixtures by transferring the contents from the bottles into an Erlenmeyer flask, rinsing any remaining solution into the flask with deionized water and adding three drops of phenolphthalein indicator. Titrate the solution to a pale pink end point.
Data:
Part A: Unknown alcohol #3 density 0.7914 g/mL molar mass 32.04 g/mol Unknown ester #3 density 0.9342 g/ mL molar mass 74.08 g/mol HCl 0.3 molarity Mass bottle
Bottle # Initial weight Weight plus HCl Final weight
1 17.6670g 23.4250g 28.7826g
1/A 19.9177g