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Topic: determining the number of moles?  (Read 4330 times)

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Offline whittfred

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determining the number of moles?
« on: August 14, 2007, 09:33:17 AM »
can someone please help with this question?  "Determine the number of moles of CaCl2 in 38.0g of CaCl2-"
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Offline Yggdrasil

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Re: determining the number of moles?
« Reply #1 on: August 14, 2007, 06:31:19 PM »
Divide the mass by the molecular weight of CaCl2.
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Offline whittfred

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Re: determining the number of moles?
« Reply #2 on: August 14, 2007, 07:44:28 PM »
I get 2.92mol is this correct?
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Offline constant thinker

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Re: determining the number of moles?
« Reply #3 on: August 14, 2007, 09:15:05 PM »
No, you did it backwards.

Molecular weight of CaCl2 is 110.9834.

I got about .34mols CaCl2.

Quick way.
38/110.9834=.34

Way that shows more.
38g CaCl2 * (1 mol/110.9834g)
grams cancels and you're left with mols CaCl2
38*(1/110.9834)=.34
.34 mols CaCl2
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