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mutantmushroom
The Mutant



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Im stuck on another chemistry problem
#19290213 - 12/17/13 07:25 PM (10 years, 2 months ago) |
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10 g of Oxygen can make _ g of Aluminum Oxide
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Uzziel
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Re: Im stuck on another chemistry problem [Re: mutantmushroom]
#19290236 - 12/17/13 07:30 PM (10 years, 2 months ago) |
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Are we assuming you have infinite amounts of Al?
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SkeletalSpore
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Re: Im stuck on another chemistry problem [Re: mutantmushroom]
#19290248 - 12/17/13 07:32 PM (10 years, 2 months ago) |
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I remember doing problems like that in grade 10 general science I would've definetely helped you if I remembered...
I think you supposed to convert oxygen into moles first... and Aluminum oxide is Al2O3... so you do something with that lol
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the mad machinest
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Re: Im stuck on another chemistry problem [Re: SkeletalSpore]
#19290266 - 12/17/13 07:36 PM (10 years, 2 months ago) |
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from wiki:
hope this helps
" 1. First, find the moles of each.
Grams -> moles
Given gram x 1 mol/molar mass
Molar mass Al: 26.98 g/mol
Molar mass O2: 32.00 g/mol
10.0 g Al x 1 mol Al/26.98 g Al = 0.3706 mol Al
19.0 g O2 x 1 mol O2/32.00 g O2 = 0.5938 mol O2
2. Then using the balanced equation, set up a mole ratio: Coefficients/Number of moles.
4 Al/0.3706 mol Al = 3 O2/x
We pretend we don't know the moles of O2.
By crossing multiplying, we find x = 0.2780 mol O2, which is less than 0.5938 mol O2. This tells us we will have EXTRA O2, and that Al is our limiting reactant.
3. Do a regular stoichiometry problem:
Molar ratio: 2 mol Al2O3 : 4 mol Al .... which can be reduced to 1 mol Al2O3 : 2 mol Al
Molar mass Al2O3: 101.96 g/mol
10.0 g Al x 1 mol Al/26.98 g Al x 1 mol Al2O3/2 mol Al x 101.96 g Al2O3/1 mol Al2O3 = 18.895 g Al2O3
Sig figs... 18.9 g Al2O3
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koods
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Aluminum Oxide by weight is 47.07% oxygen. (The Merck index is really handy)
10/.4707=21.244g
Mad machinist gave you the amount of alumina if you had 10g of aluminum.
10/.5293=18.892g
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NotSheekle said “if I believed she was 16 I would become unattracted to her”
Edited by koods (12/17/13 08:09 PM)
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mutantmushroom
The Mutant



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Re: Im stuck on another chemistry problem [Re: koods]
#19290387 - 12/17/13 08:05 PM (10 years, 2 months ago) |
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ya how much aluminum do you mix with 10 g of xQuote:
koods said: Aluminum Oxide by weight is 47.07% oxygen. (The Merck index is really handy)
10/.47.07=21.244g
thank you!
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fiddle



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Re: Im stuck on another chemistry problem [Re: mutantmushroom]
#19290393 - 12/17/13 08:06 PM (10 years, 2 months ago) |
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Grams to moles to moles to grams.
It's a stoichiometry and limiting reagents problem. Assuming you have an infinite supply of Al, then O2 becomes your limiting reagent and it simply becomes as stoichiometry problem.
Write out the chemical reaction.
How many moles of O2 do you have per 10g? How many moles of O2 react per mole of Al? How many moles of AlO can be produced? How grams of AlO is that?
Grams to moles to moles to grams.
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koods
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Re: Im stuck on another chemistry problem [Re: fiddle]
#19290426 - 12/17/13 08:15 PM (10 years, 2 months ago) |
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Quote:
fiddle said: Grams to moles to moles to grams.
It's a stoichiometry and limiting reagents problem. Assuming you have an infinite supply of Al, then O2 becomes your limiting reagent and it simply becomes as stoichiometry problem.
Write out the chemical reaction.
How many moles of O2 do you have per 10g? How many moles of O2 react per mole of Al? How many moles of AlO can be produced? How grams of AlO is that?
Grams to moles to moles to grams.
Except alumina is Al2O3
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NotSheekle said “if I believed she was 16 I would become unattracted to her”
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fiddle



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Re: Im stuck on another chemistry problem [Re: koods]
#19290439 - 12/17/13 08:18 PM (10 years, 2 months ago) |
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-------------------- Tickle my bassline.
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mutantmushroom
The Mutant



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Re: Im stuck on another chemistry problem [Re: fiddle]
#19290445 - 12/17/13 08:20 PM (10 years, 2 months ago) |
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heres another one i need help with 5 grams of water will make how many Liters of Oxygen at STP
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Uzziel
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Re: Im stuck on another chemistry problem [Re: mutantmushroom]
#19290467 - 12/17/13 08:26 PM (10 years, 2 months ago) |
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5g of H2O = ?L O2 at STP
You need to figure out how to do these limiting reagent problems.
So what do you know?
1g of water = 1 mL of water for reference
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koods
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Re: Im stuck on another chemistry problem [Re: mutantmushroom]
#19290484 - 12/17/13 08:32 PM (10 years, 2 months ago) |
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Oxygen weighs 1.429 g/l at 0°C (STP)
Water is 88.81% oxygen.
5*.8881/1.429 = 3.107 liters
Yeah, OP. You need to learn how to do these. I'm cheating by using the Merck index so I don't have to do all that molar shit.
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NotSheekle said “if I believed she was 16 I would become unattracted to her”
Edited by koods (12/17/13 08:33 PM)
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fiddle



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Re: Im stuck on another chemistry problem [Re: mutantmushroom]
#19290511 - 12/17/13 08:38 PM (10 years, 2 months ago) |
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Gas law problem, PV=nRT. Grams of H2O to moles of O2, figure out what STP is. Plug and chug.
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