Determining Rate Constant for Hydrolysis of Ethyl Lactate with Acid Catalysis?

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SUMMARY

The discussion focuses on determining the rate constant for the hydrolysis of ethyl lactate using acid catalysis, specifically with hydrochloric acid (HCl) at a concentration of 0.01023 M. The provided data includes the mass of ethyl lactate (0.5956 grams) and various titration volumes from NaOH standardization. The rate equation discussed is -d[OH-]/dt = k[OH-][EtL], but there is confusion regarding the concentration of hydroxide ions (OH-) and the role of titrations in the experiment. Clarification is needed on the measurements and the significance of the titration data.

PREREQUISITES
  • Understanding of chemical kinetics and rate laws
  • Knowledge of acid-base titration techniques
  • Familiarity with the hydrolysis reaction of esters
  • Basic proficiency in stoichiometry and concentration calculations
NEXT STEPS
  • Calculate the concentration of hydroxide ions (OH-) in the reaction mixture
  • Review the principles of acid-catalyzed hydrolysis reactions
  • Learn about the significance of titration data in determining reaction rates
  • Explore the derivation of the rate constant from experimental data
USEFUL FOR

Chemistry students, laboratory technicians, and researchers involved in kinetics studies or ester hydrolysis experiments will benefit from this discussion.

sarahrpol
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Homework Statement


Hydrolysis of ethyl lactate

Determine the value of the rate constant for the hydrolysis of ethyl lactate from the following data.

Mass of ethyl lactate (grams): 0.5956
Concentration of stock HCl solution (M): 0.01023

Standardization titration volumes (of NaOH):

Run Vi (mL) Vf(mL)
1 0.60 15.58
2 15.58 30.66
3 30.66 45.66

Kinetics data:
Run Reaction time (seconds) Vi(mL) Vf(mL)
0 0
1 308 1.72 4.32
2 742 4.32 8.88
3 1303 8.88 14.84
4 1910 14.84 21.66
5 2550 21.66 29.06

Rate constant = ?

Homework Equations


equations are below

The Attempt at a Solution


the rate equation is -d[OH-]/dt = k[OH-][EtL]

but I'm not sure how to find the concentration of OH and the concentration of Ethyl lactate is 0.01203

and then a = 1/2[OH-]o + [Etl]o
1/a-x - 1/a = kt
 
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What are the titrations for? What do they determine?

OH- is just a catalyst and its concentration doesn't change during the hydrolysis, so your rate equation can't be right.
 
This is really not set out clearly enough to understand or help with.
What are Vi, Vf? What is measured how?
Is this acid catalysis?