Sciencemadness Discussion Board - HOCOCOOH.2H2O AND (COOH)2.2H2O

HOCOCOOH.2H2O AND (COOH)2.2H2O

CHRIS25 - 28-10-2012 at 03:47

Sometimes I am so surprised at the multitude of names for a single chemical. But this entry in a catalogue really seems ridiculous, or is it me?

The entry goes like this: Oxalic acid Dihydrate HOCOCOOH.2H2O 93euros per Kg. And on 50 pages later I have Ethanedioic Acid 2 water (COOH)2.2H2O 500grams at 19.46euros - so much cheaper. They have the same formula, they have the same assay, and baker analysed, they seem to have the same analysis as listed, I find no differences except in the breakdown of impurities, the more expensive one lists the impurities and seems to list different chemicals in the oxalic acid, but these are all withh hundreds of zeros after the "point" IE 0.0005%. So what is this, a new kind of chemistry ingredient/language hidden in the price? One is for extreme analysis and purity and the other for people like me? (olde tyme photographers)

[Edited on 28-10-2012 by CHRIS25]

Ephesian - 28-10-2012 at 09:00

What's in a name? That which we call a rose
By any other name would smell as sweet.

CHRIS25 - 28-10-2012 at 09:56

Quote: Originally posted by Ephesian

What's in a name? That which we call a rose
By any other name would smell as sweet.

Very poetic.....but the price of the two, as I said, I do not understand, thereby making one rose of a diffeent constitution than the other...perhaps it is a daffodil in disguise?

Fossil - 28-10-2012 at 10:17

Quote: Originally posted by CHRIS25

I find no differences except in the breakdown of impurities, the more expensive one lists the impurities and seems to list different chemicals in the oxalic acid, but these are all withh hundreds of zeros after the "point" IE 0.0005%.

[Edited on 28-10-2012 by CHRIS25]

You answered your own question.

One is more stringently analyzed then the other, and therefore for analytical work, ect. The other is for work that does not require such precision and purity.

kristofvagyok - 28-10-2012 at 10:40

Quote: Originally posted by CHRIS25

So what is this, a new kind of chemistry ingredient/language hidden in the price? One is for extreme analysis and purity and the other for people like me? (olde tyme photographers)

Analytics samples are often really-really expensive. Best example is the Sigma catalog, simply search for water, you will be surprised

For the two price and for the two name. Some chemical manufacturers make their catalog with almost all of the possible name of the chemicals, but they usually refer the other also, e.g.: oxalic acid XYeur/kg, also at pg. 1234 at ethanedioic acid.

P.S.: that price for oxalic acid is much, usually we buy it for 10-15eur/kg.

CHRIS25 - 28-10-2012 at 11:23

Thanks. At least I know, the more expensive is for more precisions lab work.

arsphenamine - 28-10-2012 at 13:47

Chris,

you are noticing several evolutionary stages of chemical nomenclature, so the confusion/vexation is natural.

In the USA, what you want is called "technical grade".

CHRIS25 - 28-10-2012 at 14:32

Thanks, What would the other grades be then?

Fossil - 28-10-2012 at 18:25

http://www.reagents.com/products/reagents/grades.html

Technical can also mean that the purity listed is not guaranteed.

woelen - 30-10-2012 at 12:36

Quote: Originally posted by arsphenamine

[...]

In the USA, what you want is called "technical grade".

I do not fully agree with this remark. For home chemistry experiments, technical grade can be useful, but many times it is not. For instance, I have technical grade manganese dioxide, but I hardly consider it useful for experiments with manganese salts, because it contains a LOT of iron as well. I also have technical grade ferrous sulfate, but this stuff contains so much brown rust-like material that it is hardly useful for aqueous chemistry experiments and I can add many more technical grade chemicals to the list.

Some chemicals are useful in technical grade but certainly not all of them. For my experiments I prefer general lab reagent grade or synthesis grade. This is good enough for most experiments, but is still a lot cheaper than analytical reagent grade.