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How do I figure out empirical formulas when I'm given mol of certain atoms?
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Topic: How do I figure out empirical formulas when I'm given mol of certain atoms? (Read 11393 times)
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Edgar9760
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How do I figure out empirical formulas when I'm given mol of certain atoms?
«
on:
October 10, 2011, 04:32:15 AM »
The problem given is:
Determine the empirical formulas of the following compounds:
(a) 0.039 mol of iron atoms combined with 0.052 mol of oxygen atoms
(b) 0.903 g of phosphorous combined with 6.99 g of bromine
(c) A hydrocarbon with 79.9 mass % carbon
I don't know where to start.
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Edgar9760
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Re: How do I figure out empirical formulas when I'm given mol of certain atoms?
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Reply #1 on:
October 10, 2011, 04:43:36 AM »
I started (a) and all I could think of was converting the moles given moles to grams getting the following:
2.18g of iron and 0.832g of oxygen.
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Borek
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Re: How do I figure out empirical formulas when I'm given mol of certain atoms?
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Reply #2 on:
October 10, 2011, 04:55:02 AM »
So you already went in the wrong direction. Empirical formula is about ratio of number of atoms in the molecule - that is much closer to moles than to masses.
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ChemBuddy
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Edgar9760
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Re: How do I figure out empirical formulas when I'm given mol of certain atoms?
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Reply #3 on:
October 10, 2011, 05:01:52 AM »
Ok I tried once more and the answer I got was Fe3O4. The numbers being subscripts. Is that correct?
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Borek
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Re: How do I figure out empirical formulas when I'm given mol of certain atoms?
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Reply #4 on:
October 10, 2011, 06:02:04 AM »
Fe
3
O
4
it is.
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ChemBuddy
chemical calculators - stoichiometry, pH, concentration, buffer preparation,
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Edgar9760
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Re: How do I figure out empirical formulas when I'm given mol of certain atoms?
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Reply #5 on:
October 10, 2011, 08:07:06 AM »
Thank you. As for part (c), I'm not sure which hydrocarbon the problem is referring to. How do I find that out?
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fledarmus
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Re: How do I figure out empirical formulas when I'm given mol of certain atoms?
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Reply #6 on:
October 10, 2011, 08:29:33 AM »
What is the definition of a hydrocarbon?
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Edgar9760
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Re: How do I figure out empirical formulas when I'm given mol of certain atoms?
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Reply #7 on:
October 10, 2011, 06:41:58 PM »
A compound of hydrogen and carbon, such as any of those that are the chief components of petroleum and natural gas.
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fledarmus
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Re: How do I figure out empirical formulas when I'm given mol of certain atoms?
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Reply #8 on:
October 10, 2011, 09:16:34 PM »
Good - and if it contains only hydrogen and carbon, and it is 79.9% carbon, what would the molecular formula be?
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How do I figure out empirical formulas when I'm given mol of certain atoms?