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Topic: Please check solution on Al2O3  (Read 11356 times)

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Offline oceanmd

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Please check solution on Al2O3
« on: February 25, 2008, 09:30:28 PM »
Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide: 4Al+3O2=2Al2O3. In a particular experiment, the reaction of 2.5 g of Al with 2.5 g of O2 produced 3.5 g of Al2O3. The % yield of the reaction is ………

2.5 g Al=9.27 x 10^-2 mol Al
2.5 g O2 = 7.81 x 10^-2 mol O2
Al is limiting
9.27 x 10^-2 mol Al= 4.64 x 10^-2 mol Al2O3 = 4.73 g Al2O3
3.5 g/4.73g x 100% =74%

Is this correct? Thank you very much.

Offline ARGOS++

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Re: Please check solution on Al2O3
« Reply #1 on: February 25, 2008, 09:40:19 PM »

Dear Oceanmd;

Ok!, ─   But my watch tells me that it is now 3.40 in the Morning!
So have a good night.   (Where are the 3 ciphers?)


Good Luck!
                    ARGOS++


Offline enahs

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Re: Please check solution on Al2O3
« Reply #2 on: February 25, 2008, 09:40:50 PM »
I did not put the numbers in a calculator, but crunching them in my head it all looks reasonable.

You clearly have the method down which is the important part.

Start asking yourself questions like "do the units match up" in the end, and think about in general if the values are in the right direction (i.e. should it be larger then or smaller then something), etc.

Offline oceanmd

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Re: Please check solution on Al2O3
« Reply #3 on: February 25, 2008, 09:50:35 PM »
ARGOS,

Thank you very much. Good night.

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