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Percentage composition of nitrogen in ammonium sulfate? (2 Viewers)

failedtrials

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So far i've found the moles of ammonium. What is a relevant equation to find the moles for nitrogen?
 

Queenroot

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Wat, elaborate
Do you want the chemical formula for it? Then it is just a simple google search.
If you want an equation, that means you're reacting it with something/it is a product, so tell me what those are.
 

seventhroot

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Wat, elaborate
Do you want the chemical formula for it? Then it is just a simple google search.
If you want an equation, that means you're reacting it with something/it is a product, so tell me what those are.
I guess this is why he failed trials hue ;)
 

failedtrials

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I think s/he means in general? In this case, mass of nitrogen/mass of molecule
I'll just post the whole question.

You are given to analyse the concentration of nitrogen in a sample of ammonium sulfate fertilizer. Precipitate the sulfate ion from solution using barium nitrate and then use the mass of precipitate formed to determine concentration of nitrogen.

Mass of fertilizer: 14.21
Mas of barium sulfate precipitated: 1.15
Determine percentage of composition of nitrogen in fertilizer
 

Queenroot

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I'll just post the whole question.

You are given to analyse the concentration of nitrogen in a sample of ammonium sulfate fertilizer. Precipitate the sulfate ion from solution using barium nitrate and then use the mass of precipitate formed to determine concentration of nitrogen.

Mass of fertilizer: 14.21
Mas of barium sulfate precipitated: 1.15
Determine percentage of composition of nitrogen in fertilizer
Here's your equation:

Ba(NO3)2(aq) + (NH4)2SO4(aq) → 2NH4NO3(aq) + BaSO4(s)
 

Queenroot

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n = m/mm
moles of BASO4 = 1.15/(molar mass of BASO4 I ceebs calculating)
From equation we see that there are 2 moles of nitrogen in ammonium sulfate.

We now take the moles of BASO4 and multiply this by 2.
So moles of Nitrogen = moles of BaSO4 x 2

To find the original conc, are they asking for w/w% or w/v%?
 

Queenroot

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It didn't mention that, but i think its safe to assume w/w%.
Okay, then from the moles of Nitrogen you'd find the mass.
So Mass of Nitrogen = moles of Nitrogen x molar mass of nitrogen.

Then iirc you put:
(mass of nitrogen/14.21) x 100 = w/w%

I'm not sure, been ages since I did this. Someone pls confirm.
 

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