Bandil (Hive Bee)
12-19-01 11:36
No 248990
      Purity of NaEtSO4 calculation question  Bookmark   

Hi!

Swim had made 110 g of supposed NaEtSO4 using antonchio's(hope i spelled it right) route. He attempted to test the purity the following way:

about 8 grams og CaCl2 was dissolved in 350 mL not-so-cold water. 5,2 gram sample of the NaEtSO4 was dissolved in 200 mL of water. The NaEtSO4 was poured into the beaker, containing the CaCl2, and white precipitate was observed. The precipitate was filtered and dried after the mixture had cooled for hour. It weighted 0.95 grams dry.

Here is what swim calculated from that:

M(CaSO4)=136 g/mol
n(CaSO4)=0.95g/136(g/mole) = 6.99 mmole Sulfate.
m(Na2SO4)=6.99E-3 * M(Na2SO4) = 0.83 g of sodium sulfate.

This should mean that swims ethylsulfate is (5.2-0.83)/5.2*100 percent pure = 84%

Considering the poor circumstances it was made under(ether boiling etc), swim thinks its a bit high? Swim supposes that it is pure enough for the next stage, how do you feel about this?

Thanks alot!

Regards
Peter
 
 
 
 
    Antoncho
(Official Hive Translator)
12-19-01 19:14
No 249133
      Re: Purity of NaEtSO4 calculation question  Bookmark   

My name spells Antonchosmilewink It's a transcription of a russian translation of a mexican derivative of the name 'Anton' - the suffix itself comes from one of Castaneda's books ("- What's up, Khenarcho?" smile) Do you by chance know how it spells in the original text?

As for the purity - i think boiling ain't a problem in this case - think of it, why should it? (unless it created much tar, that is).
Unfortunately, your results aren't correct since you used way too much water. Remember, 100 ml aqua dissolves 200 mg CaS)4, and presence of inorganic cations only increases its solubility. So i guess, the real amt of Na2SO4 in your salt is >2 g ---> NaEtSO4 purity < ~60%

It's still good for the next step, just make sure you calculate your NaNO2 amt based not on NaEtSO4, but on the whole weight of the salts' mixtr.

This purity test of course sucks (as i 've noted previously) and won't give you a precise result ever.

I'm eagerly awaiting your results, PM me if you have any Q's you think i could help with (as this seems to bee just a conversation beetween us two at this point)

Bee sure that a)your NaEtSO4 is dry b) NaNO2 is melt-dried (BTW, it's better to shuffle it up beefore it completely solidifies, otherwise you're gonna have a hard time scraping it off the dish) c) you mix the ingredients in a coffee grinder as finely as your patience (and the grinder) will allow.

Antoncho