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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: jgrayczyk on August 02, 2017, 02:11:32 AM

Title: Sodium hydride vs Potassium tert-butoxide
Post by: jgrayczyk on August 02, 2017, 02:11:32 AM
Which is a stronger base NaH or K-OtBU?
Title: Re: Sodium hydride vs Potassium tert-butoxide
Post by: rolnor on August 02, 2017, 05:44:48 AM
NaH is stronger.
Title: Re: Sodium hydride vs Potassium tert-butoxide
Post by: Vidya on August 04, 2017, 02:12:18 AM
Compare acidity of their conjugate acids.
In NaH , H-  is the base and its conjugate acid is H2
K O tert- Bu, base is tert -Butoxide  and its conjugate acid is tert-butanol .Now H on the oxygen of tert -butanol is more acidic then H of H2 because of the difference in the electronegativity of H and Oxygen atoms.
Strong acids give weak conjugate base so if I compare   tert -Butoxide  with hydride ion then hydride  is stronger base.Or you can simply compare their pKb values.
Title: Re: Sodium hydride vs Potassium tert-butoxide
Post by: SamuelPi on October 29, 2017, 08:49:48 AM
That makes sense thanks Vidya, I though NaH would be stronger.
Title: Re: Sodium hydride vs Potassium tert-butoxide
Post by: Babcock_Hall on October 29, 2017, 09:59:50 AM
Quote from: jgrayczyk on August 02, 2017, 02:11:32 AM
Which is a stronger base NaH or K-OtBU?
@OP,  Find the pKa values and compare them.
Title: Re: Sodium hydride vs Potassium tert-butoxide
Post by: Babcock_Hall on October 30, 2017, 08:33:40 AM
@OP, I just looked up the pKa of H2, and I found it to be 35.  See what you make of that.