Acid-Base Chemistry Question

[Charles Darwin]

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(CH3)3COH + KOH <---> (CH3)3COK + H2O

Will the reaction take place as written?

Thank you!

 

[Sutton]

(CH3)3COH + KOH <---> (CH3)3COK + H2O

Will the reaction take place as written?

Thank you!

How is this an acid-base reaction? You are reacting a tertiary alcohol with a strong base.

 

[Pre-Med Village]

Because alcohols are weaker acids than water, alkoxide ion formation in yield requires a stronger base than potassium hydroxide, such as sodium hydride. Some product will form in this reaction, but the equilibrium will be far to the left.

 

[IH8ColdWeath3r]

^ pKa water = 16
pKa alcohol ~16

most generic alcohols like the one listed above have a pKa of around 16, ones not attached to a carbonyl at least.

 

[Pre-Med Village]

tert-Butanol has a pkA ~ 18, so it's about 100 times less acidic than water

The pkA values of normal alcohols range from 16 to 19

 

[Charles Darwin]

Because alcohols are weaker acids than water, alkoxide ion formation in yield requires a stronger base than potassium hydroxide, such as sodium hydride. Some product will form in this reaction, but the equilibrium will be far to the left.

That's what I thought. I appreciate the response! 👍

 

[BerkReviewTeach]

According to my undergrad O chem book, t-butanol has a pKa of 17.8, 2-propanol 16.9, ethanol 15.9, methanol 15.5, and water 15.7.

Keq for the OP's reaction should be about 1/200 as written. In some cases you could entice the reaction to go in the forward direction by distilling away the product, but water's boiling point is higher than t-butanol's boiling point (82.2 degreesC), so that won't work. Unless you could add a dehydrating agent that won't interfere with the reaction to remove water from the solution, that is a useless reaction (as written).