Sciencemadness Discussion Board

Thoughts on acids/bases

sternman318 - 27-5-2011 at 13:38

Well in my musings on chemistry iI have been thinking about acids and bases...

It appears that acids are MUCH more useful in chemistry than bases are. I feel like I see many more reactions that are facilitated by low pH than high pH. Is this true?

If the above is true, why exactly is this true? Is it because it is a small particle with charge and can thus easily impart changes to molecules ( e.g. momentarily contorting a molecules shape ( because of its charge) to facilitate the reaction with another molecule), and because it pretty much only needs a pair of electrons for a bond, it bond easily? though, i feel like that last part is false.

As for bases, I am not too sure why they would facilitate reactions. My thinking, is that it is almost incorrect to think of bases as ... "bases"... but as an 'anti-proton', whose usefulness comes from reducing the presence of H+?

I am just amazed how important pH is to chemistry overall ( aqueous chemistry, atleast).

bbartlog - 27-5-2011 at 14:19

Well, that's sort of like saying the front wheels on your car are much more useful than the rear ones. Or something similarly inane. I believe the answer is no.

ScienceSquirrel - 27-5-2011 at 14:29

It is hardly surprising that acids and bases are catalysts for a lot of reactions and pH is important when you look at the fact that a lot of reaction steps involve the transfer of a proton.
Bases are very important as well, consider a nucleophile HuH, the base Nu- can be orders of magnitude more nucleophilic.
In organic chemistry a lot of side issues like solubility and the strength of the acid or base comes in to play. Triethylamine may be excellent for promoting one reaction but pyridine will be far better for another.

redox - 8-6-2011 at 16:08

It seems (to me at least) that simple home chemistry revolves much more around acids than bases, you're right.
However, once you get into more complicated alkoxide, amine, and alkylmetal chemistry, the get much more important.

smuv - 8-6-2011 at 16:31

I could give you the mundane, for any acid catalyzed reaction, there is a base the acid is acting upon, and vice versa. But I get what you mean, and I thought that way too when I first started up in amateur chemistry. The thing is, I feel that most of my chemistry at work involves bases!

I think it comes down to, grignards, organolithiums and organic amines are not OTC, while all the acids I can think of are otc or easily made from OTC precursors.

edit: in essence what redox said ;)



[Edited on 6-9-2011 by smuv]

woelen - 8-6-2011 at 23:35

For the home chemist there also are quite a few interesting inorganic reactions involving bases. Think of the interesting reduction of permanganate to green manganate(VI) and then to blue manganate(V) and finally to brown manganate(IV) and hydrous MnO2. Another very interesting thing is the production of peroxo chromates in strongly alkaline environments. Also the making of peroxo vanadates and also hypovanadates requires high pH.

It is just depending on the kind of chemistry you do. Acids are important, but bases also. Even a starting amateur chemist needs both of them.

ldanielrosa - 9-6-2011 at 00:52

I make my own soap, and that just doesn't happen without a base (NaOH and KOH).

Bases are the workhorse for making biodiesel too, but it's more efficient if you catalyze with acid _first_ to get rid of the FFAs then base to finish the job.


LanthanumK - 9-6-2011 at 03:01

The production of metal oxides and hydroxides, especially transition metal ones, requires the use of bases, while the production of metal salts usually requires acids. But I did notice when I used to conduct chemistry experiments that the HCl bottle went down about 3 times faster than the NH3 bottle (I didn't use any stronger base).

sternman318 - 9-6-2011 at 10:17

Thanks everyone. i think you're all right, and that its mostly a result of me merely being an amateur home-chemist.

Are there any other solvents that exhibit such dissociation?

redox - 9-6-2011 at 16:46

What dissociation?

sternman318 - 9-6-2011 at 17:02

Quote: Originally posted by redox  
What dissociation?

H2O <-> OH- + H+
In other words, are there other solvents that exhibit an analagous acid/base behavior?

The WiZard is In - 9-6-2011 at 17:04

Quote: Originally posted by sternman318  
Well in my musings on chemistry iI have been thinking about acids and bases...



Well if you compare world wide production of H2SO4 vs.
Na and KOH you will know which is used more.

I being a suspicious person would suspect that it has nothing to do
with chemistry and everything to do with $$$$.
What sells the most — is made the most.

LanthanumK - 10-6-2011 at 03:12

Sternman318: This dissociation equilibrium is typical of ionic substances. It should happen in ionic liquids. There are some substances that are not ionic but do dissociate under certain circumstances, such as iodine trichloride.