Question

Why only CONCENTRATED sulfuric acid a dehydrating agent?? why not dilute???

Answer 1

Can u help?? please

Answer 2

@wolfe8 pls

Answer 3

I'd guess because it would absorb the water to dilute itself? (layman's words)

Answer 4

dehydration usually starts with protonation right? like if u want to dehydrate ethanol to get ethene ,, the (H+) ion given by sulphuric acid protonates the oxygen of ethanol and then H20 is lost easily...... so in that case any proton donor (acid) must be a dehydrating agent no

Answer 5

Ohhhh that kind of dehydration. Isn't sulphuric acid the catalyst? Lemme check.

Answer 6

no no no...its a strong dehydrating agent

Answer 7

For a dehydrating agent to work... it must not contain water itself

Answer 8

http://chemistry.about.com/od/chemistrydemonstrations/a/acidsugardemo.htm

The sulfuric acid removes water from the sugar in a highly exothermic reaction, releasing heat, steam, and sulfur oxide fumes.

So yea I would agree with Thomaster.

Answer 9

so anything that doesnt contain water acts as a dehydrating agent???

Answer 10

The acid catalysts normally used are either concentrated sulphuric acid or concentrated phosphoric(V) acid, H3PO4.

http://www.chemguide.co.uk/organicprops/alcohols/dehydration.html

And that's why I thought it's only a catalyst.

Answer 11

ohhk! ....but im really confused about why only Concentrated sulfuric acid is used

Answer 12

you wouldn't use a wet towel to dry your hands right? it doesn't work

Answer 13

haha....i got that part!

Answer 14

But still ,,, u could use a higly concentrated nitric acid no???? its not wet either

Answer 15

Nitric acid is weak acid. I'd guess something weak is not good.

Answer 16

Or any other Conc acid could have been used as a dehydrating agent

Answer 17

Owait, is that acetic? I shouldn't be doing chemistry at 6 am lol

Answer 18

@thomaster ,, i agree with ur logic about not containing water.....but i think that works out only with those ANHYDROUS dehydrating agents like anhy Al203 ,,P2O5 ,,,and all

Answer 19

I heard somewhere that inorder to be an efficient dehydrating agent ,, it must not be a strong acid

Answer 20

and when H2SO4 is concentrated,, it loses most of its ACID properties....

Answer 21

this is the answer to my question ....but still i cant figure out why " inorder to be an efficient dehydrating agent ,, it must not be a strong acid"

Answer 22

maybe @Frostbite can give you a more "technical" answer :P

Answer 23

THanks!

Answer 24

ok...again i got a partial answer...they said that the ACID Properties and other properties that sulfuric acid possesses like " Oxidizing propery"......interfere with the normal dehydration reaction ,producing side products.......ok got it ......but why not use any other random "NOT WET" reagent like nitric acid or something???

Answer 25

@Frostbite please can u help me out?????

Answer 26

I can't find any good reason why diluted won't work, except what is already said.

Answer 27

ok..But why not the other random reagents?

Answer 28

HNO3 or HCl 'look' equally good as acids just like sulfuric acids..