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MyCoFiend420
ShRoOmEr



Registered: 12/08/08
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Help with chemistry problem?
#22329324 - 10/03/15 04:49 PM (8 years, 3 months ago) |
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I'm having trouble trying to figure out what to do with is problem as it it's different than the ones on the paper and in my notes. Also I cannot seem to find any examples like this one in the book. The letters represent a number a=3 b=4 c=8 and D=2. Any help would be much appreciated , the problem is " what is the formula mass of a coal with a formula of C1abHbdScOd" (all lower case letters and numbers are subscripts) . thank you.
-------------------- There are thing known,and things unknown and in between them are the doors of perception
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micro
bunbun has a gungun



Registered: 05/09/03
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Re: Help with chemistry problem? [Re: MyCoFiend420]
#22330031 - 10/03/15 08:01 PM (8 years, 3 months ago) |
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so it's C32H42S8O2 ???
if that's the case just multiply by the molar masses and sum: 12.01 * 32 + 1.01 * 42 + 32.07 * 8 + 16 * 2
if that isn't the formula (which does not seem like a realistic compound, anyway) then i don't understand what is being asked in that part
also, coal is just an alletrope of carbon
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TheMaster
PATIENCE


Registered: 07/13/13
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Re: Help with chemistry problem? [Re: micro]
#22331601 - 10/04/15 07:40 AM (8 years, 3 months ago) |
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Quote:
MyCoFiend420 said: The letters represent a number a=3 b=4 c=8 and D=2. " what is the formula mass of a coal with a formula of C1abHbdScOd".
Is that 1 after carbon a typo? If so, then it will be C34H42S8O2
Then just plug in atomic weight for the different elememts, multiply by the subscript numbers and add the results for the formula weight in g/mol
Quote:
micro said: so it's C32H42S8O2 ???
if that's the case just multiply by the molar masses and sum: 12.01 * 32 + 1.01 * 42 + 32.07 * 8 + 16 * 2
if that isn't the formula (which does not seem like a realistic compound, anyway) then i don't understand what is being asked in that part
also, coal is just an alletrope of carbon
Your approach is 100% correct, but looks like a minor typo that should be C34.
Since coal is a metamorphic product, you have a transition from organic chemistry towards the inorganic realm. A quick google image search reveals various coal compositions from around the world. http://www.google.com/search?q=coal+structure&safe=off&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AVqFQoTCIft7bL2qMgCFcHXHgodlogASg
Although it is mostly carbon, coal is not really an allotrope of carbon. Allotropes are pure molecular forms of a single type of element
-------------------- "Live as if you were to die tomorrow. Learn as if you were to live forever." Mahatma Gandhi
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micro
bunbun has a gungun



Registered: 05/09/03
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Re: Help with chemistry problem? [Re: TheMaster]
#22333098 - 10/04/15 02:49 PM (8 years, 3 months ago) |
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Quote:
TheMaster said: Your approach is 100% correct, but looks like a minor typo that should be C34.
Thanks!
Quote:
TheMaster said: Since coal is a metamorphic product, you have a transition from organic chemistry towards the inorganic realm. A quick google image search reveals various coal compositions from around the world. http://www.google.com/search?q=coal+structure&safe=off&source=lnms&tbm=isch&sa=X&ved=0CAcQ_AVqFQoTCIft7bL2qMgCFcHXHgodlogASg
Although it is mostly carbon, coal is not really an allotrope of carbon. Allotropes are pure molecular forms of a single type of element
Hmm, yeah according to the wiki coal doesn't always become amorphous carbon.
It shoudn't have sulphur and oxygen though, which is what I was getting at.
-------------------- Any research paper or book for free (Avatar is Maxxy, a character by Mizzyam, RIP)
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TheMaster
PATIENCE


Registered: 07/13/13
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Re: Help with chemistry problem? [Re: micro]
#22334204 - 10/04/15 07:04 PM (8 years, 3 months ago) |
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There are many types of coal. Some have higher levels of sulfur than others, some have more oxygen, or more nitrogen, etc. It's all remnants of the original organic matter that has undergone changes towards a more stable conformation. Since the carbon carbon bond is more favorable, we see an ever decreasing amount of these elements within the crystalline matrix.
Graphite is an allotrope of carbon that will form after anthracite has undergone further heat and pressure treatment. It could be seen as a type of coal, but it is not used as a fuel like the more combustible varieties are.
-------------------- "Live as if you were to die tomorrow. Learn as if you were to live forever." Mahatma Gandhi
Edited by TheMaster (10/05/15 06:35 PM)
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