Dehydration of Ethanol (1 Viewer)

[Viper]

Hey guys,

I am currently revising "Identification & Production of Materials", and i was wondering why Sulfuric Acid (H2SO4) is required for the Dehydration of Ethanol.

At the moment, im guessing that it increases the activiation energy, but is that all i need to know?

Please Explain?


Cheers

 

[PoLaRbEaR]

This is just out of the Macmillan textbook:
'Ethanol can be converted back to ethene by dehydration. This can be achieved by heating ethanol with concentrated sulfuric acid, which acts as a catalyst and dehydrating agent.'

 

[ND]

http://www.kcpc.usyd.edu.au/discovery/9.2.3/9.2.3_Dehydration.html

 

[jnothman]

All you need to know (and you REALLY need to know) is that it is a catalyst.

Catalysts generally provide an alternative pathway or environment for a reaction to occur, decreasing the activation energy of the overall reaction.

 

[spice girl]

the catalyst is the acid (H+). But why sulfuric acid instead of HCl, HNO3, etc?

besides the fact that SO4 is pretty much inert, conc H2SO4 is 'dehydrating' - it absorbs water. This is necessary to drive the equilibrium towards the ethene product.

u can see this using le-chat's principle with this:
ethanol <-> ethene + H2O

removing H2O product will drive equm towards the right.

 

[hipsta_jess]

what spice girl said..
the H2SO4 takes water out of the ethanol to form the dehydrated ethene.

 

[Viper]

ahhh... thanks guys (and girls).

I thought it may have had something to do with absoring the water (but i thought of allot of things).

Thanks again


Cheers

 

[Ragerunner]

Yes when it absorbs water it shifts the equilibrium to the right

 

[sunken eyes]

the question pretty much answers itself. somethings gotta absorb the water from ethanol. its the acid.

 

[JOhnNiLiCiouS]

Originally posted by Ragerunner
Yes when it absorbs water it shifts the equilibrium to the right

woohhh... is it really an equilibrium??

anyway in the industrial chem elective, it explains it a bit more thorough. Ask your teacher to demonstate ethanol as a dehydrating agent on sugar... Hilarious!... make sure u add lots of sugar