Ergebnis in wt% von Pyrit. Wie komme ich zu dem Ergebnis?

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1 Antwort

Ich versteh die Frage nicht ganz, kannst du sie nochmal umformulieren damit ich dir helfen kann? Im Ag2S ist überhaupt kein Pyrit enthalten, Pyrit ist eine eigenständige Verbindung.

Quantom 02.02.2015, 14:36

Ok, (für die kurze Anmerkung, Deutsch ist nicht meine Muttersprache, vielleicht liegt es daran, dass es unverständlich ist.)

Vll in Englisch besser:

Pyrite was extracted by chromium reduction. PACS-2 contained 0.71 wt% pyrite.

The sulfur compounds were trapped in silver nitrate, forming silver sulfide, Ag2S.

This residue is used to quantify pyrite content, as 2 mol of Ag2S corresponds to 1 mol of pyritic iron, FeS2.

So, I dont know how has come to this result? I mean to 0.71 wt% pyrite.

And the second question: In a sample (0,206 gramm), with the extraction so I get this sample to silver nitrate to the membram filter. On the membram filter, it was weight in 0,6048 g, after drying the filter, then to: 0,6184 g. My job is to find out how much wt% pyrite is in this filter or in a sample?!

kalippo314 02.02.2015, 15:04

The first question is impossible to answer without any quantities. The calculation is mass fraction = mass of pyrit / mass of PACS-2


sec question : You have 0,6048 g silver sulfide, thats n = m/M /// n = 0,6048g / 247g/mol = 0.00245 mol.

Since 2 mol of Ag2S correspond to 1 mol of pyritic iron the calculation is: 0.00245 / 2 = 0.001225.

m (pyritic iron) = n x M /// m = 0.001225mol x 120g/mol = 0.147 g 0.147 / 0.206 = w(pyrit in sample) = 0.71.

It isnt w% btw. For w% you would have to multiply by 100. its 71w%

Quantom 02.02.2015, 16:30

Yes, exactly. I am looking for this answer. Thank you very much!!!

kalippo314 02.02.2015, 19:37

You´re welcome. Just wondering, are you studying Geology in Germany (Freiburg perhaps)? Would be a funny coincidence.

Quantom 04.03.2015, 10:26

No I am not studying in Freiburg :P Now I am studying in Denmark ;)


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