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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: myii on May 16, 2021, 03:10:55 AM

Title: Hydrolysis??
Post by: myii on May 16, 2021, 03:10:55 AM

Hi guys :)

Just wondering: whether the values of kOH and kNH3 for the hydrolysis of ethyl fluoroacetate would be higher or lower than those for the hydrolysis of ethyl chloroacetate.

It would be higher right, due to the increase rate of reaction from the hydrolysis of ethyl fluoroacetate?

Title: Re: Hydrolysis??
Post by: Orcio_87 on May 16, 2021, 06:46:18 AM

Hydrolysis rate of ester depends on concentration of hydrolysed compound + concentrations of H+ or OH-, as both ions accelerate reaction rate.

Ethyl fluoroacetate should be more reactive towards OH-, as fluorine atom make carbonyl carbon more electrophilic, so reaction rate should be higher.

Title: Re: Hydrolysis??
Post by: Orcio_87 on May 16, 2021, 11:35:35 AM

Quote

whether the values of kOH and kNH3 for the hydrolysis of ethyl fluoroacetate would be higher or lower than those for the hydrolysis of ethyl chloroacetate.

kOH (rate constant of hydrolysis) should be higher for ethyl fluoroacetate.

Second page:

https://web.viu.ca/krogh/chem331/Hydrolysis%20Lab%202006.pdf

Hydrolysis constant of CHCl₂-COOCH₃ is higher than CH₃-COOCH₂CH₃.

As of kNH₃ (rate constant of amide formation - side reaction of hydrolysis in ammonia solution) I think it also should be higher as both reactions follows the same mechanism.