[Seks]

(1) LiAlH4 in Et2O
(2) HCl in H2O

My instructor said not to use H2SO4 in H2O for step (2) as it's not recommended.  She didn't say why.  So why can't I use H2SO4 in H2O?  My initial assumption was that I can use any aqueous acidic solution? 

[agrobert]

What is the purpose of the acid?

Which acid is stronger?

[Seks]

What is the purpose of the acid?

Which acid is stronger?

Neutralize the solution.  HCl is stronger.

 

[agrobert]

The acidic work-up also protonates what?  You need a strong acid to neutralize a strong _____ efficiently.  What is your base?

[sjb]

It might be that H₂SO₄ is too viscous, so you won't be able to stir effectively and may not quench all the LiAlH₄ well.

I'm surprised you're using mineral acid to work LiAlH₄ reductions up though, what sort of scale are you talking? Typically I thought you used things like the Fieser work-up procedure - http://www.chemicalforums.com/index.php?topic=9767.msg46338, I've certainly done this on 30-40g of LAH before now...

Is this just a "chemistry en papier" question?

S

[sjb]

It might be that H₂SO₄ is too viscous, so you won't be able to stir effectively and may not quench all the LiAlH₄ well.

ERm, ranmbling again, forget that. Does H₂SO₄ (or perhaps more specifically, the sulfate and bisulfate anions) do anything else to alcohols