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

AI Thread Summary
The discussion focuses on determining the rate constant for the hydrolysis of ethyl lactate using provided experimental data, including mass and HCl concentration. Participants express confusion regarding the concentrations of hydroxide ions (OH-) and the role of titration volumes in the calculations. The rate equation presented is questioned, as OH- acts as a catalyst and its concentration remains constant during the reaction. Clarifications are sought on the meaning of initial (Vi) and final (Vf) titration volumes and whether the process is indeed acid-catalyzed. The conversation highlights the need for clearer data interpretation and methodology in calculating the rate constant.
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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?
 
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