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Topic: Arrrrr very basic problem, yet confused.  (Read 3336 times)

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Zoloft

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Arrrrr very basic problem, yet confused.
« on: February 08, 2009, 06:45:58 PM »
According to one of my labs, the atomic mass of Zinc can be determined by the balanced equation,

Zn + 2HCl ---> H2 + ZnCl2

Then it says "the number of moles of zinc metal that reacted be be calculated"

So then I use the number of moles of H2 that I calculated (we did a barometric experiment and calculated moles of H2,n, from n = PV/RT) and I do:

.00581 mol H2 x (1 mol Zn / 1 mol H2) = .00581 mol of Zn

then it says "Since all the original Zinc is consumed in this reaction, the atomic mass of zinc can thereby be determined..."

My question is, how do I determine this?

Borek

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Re: Arrrrr very basic problem, yet confused.
« Reply #1 on: February 08, 2009, 07:11:57 PM »
I suppose you know mass of zinc used?
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Zoloft

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Re: Arrrrr very basic problem, yet confused.
« Reply #2 on: February 08, 2009, 07:20:59 PM »
I suppose you know mass of zinc used?
Yes, it was .587 grams.

Obviously the Atomic mass is 65.41 g, but how do I determine this (or a number close to this) using the experimental procedure?

nj_bartel

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Re: Arrrrr very basic problem, yet confused.
« Reply #3 on: February 08, 2009, 08:03:40 PM »
MWZinc = x gramsZinc / 1 moleZinc

grams / moles

Zoloft

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Re: Arrrrr very basic problem, yet confused.
« Reply #4 on: February 08, 2009, 08:14:40 PM »
MWZinc = x gramsZinc / 1 moleZinc

grams / moles

Hmmm, so in this case the number of moles of Zinc is the moles of Zinc using the stoichiometric relationship, right?

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