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March 29, 2024, 12:38:28 pm

Author Topic: VCE Chemistry Question Thread  (Read 2313534 times)  Share 

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jgoudie

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Re: VCE Chemistry Question Thread
« Reply #915 on: May 23, 2014, 10:54:31 am »
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Fragmentation envolves the breaking up of an ion.  The 72 m/e is the mass of C5H12.  Was there a larger ion that this fragment broke up from?  Or a smaller ion that this breaks down into?  Other wise you would be looking at the formation of the parent molecular ion rather than fragmentation.

Seems the question is lacking some information.

How does one write an equation illustrating fragmentation?
C5H12
72 m/e
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Re: VCE Chemistry Question Thread
« Reply #916 on: May 23, 2014, 05:52:08 pm »
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what is delocalised electrons?

thanks

lzxnl

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Re: VCE Chemistry Question Thread
« Reply #917 on: May 23, 2014, 06:57:41 pm »
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Delocalised electrons refer to electrons that don't reside in a bond between two atoms. For instance, in benzene each carbon has an electron that isn't confined to being between two carbons in a chemical bond, but can move around all of the carbon atoms.
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Einstein

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Re: VCE Chemistry Question Thread
« Reply #918 on: May 23, 2014, 08:55:29 pm »
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Delocalised electrons refer to electrons that don't reside in a bond between two atoms. For instance, in benzene each carbon has an electron that isn't confined to being between two carbons in a chemical bond, but can move around all of the carbon atoms.

thanks mate. And is that cyclobenzene?

lzxnl

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Re: VCE Chemistry Question Thread
« Reply #919 on: May 23, 2014, 09:06:12 pm »
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It's just called benzene
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Reus

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Re: VCE Chemistry Question Thread
« Reply #920 on: May 23, 2014, 09:20:06 pm »
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Just a question, for the unbalanced equation for the production of:
Methanol from chloromethane, I got the following:

CH3Cl(g)+ OH- --> CH3OH(aq) + Cl-

However the book's answers page has it as CH3Cl(g) -OH--> CH3OH(aq) + Cl-
(with the hydroxyl group on top of the arrow)
Does that really matter? Would mine be considered wrong? Or is it just a more technical way to express it?
Thanks.
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thushan

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Re: VCE Chemistry Question Thread
« Reply #921 on: May 23, 2014, 10:19:50 pm »
+1
Same thing. There are many ways of expressing it. The answers use a shorthand form. Your equation is also correct.
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Einstein

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Re: VCE Chemistry Question Thread
« Reply #922 on: May 25, 2014, 11:45:43 am »
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could someone please give me a definition of a molecule and compound, and any examples of each.

Thanks  ;D

Reus

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Re: VCE Chemistry Question Thread
« Reply #923 on: May 25, 2014, 12:10:50 pm »
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could someone please give me a definition of a molecule and compound, and any examples of each.

Thanks  ;D
I'd define it as a molecule being formed when two or more atoms of the same element join together chemically (e.g. N2 or H2) whereas a compound is a molecule that contains at least two different elements (e.g. CO2 or NH3)
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lzxnl

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Re: VCE Chemistry Question Thread
« Reply #924 on: May 25, 2014, 12:32:34 pm »
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Compounds include ionic compounds. This is a much broader category, but doesn't include allotropes of elements like ozone. Chemical compounds (that are pure) consist of atoms of different elements that can be separated by chemical reactions.
Molecules don't; we generally think of them as consisting of atoms joined by covalent bonds, and these do include things like O3, O2 and S8.
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katiesaliba

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Re: VCE Chemistry Question Thread
« Reply #925 on: May 25, 2014, 04:50:57 pm »
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For esters in year 12, do we only use alkanols with hydroxyl groups attached to their 1st carbon?
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lzxnl

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Re: VCE Chemistry Question Thread
« Reply #926 on: May 25, 2014, 04:57:16 pm »
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They can give you other kinds of alcohols; not common though. Primary alcohols are most common in these reactions.
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katiesaliba

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Re: VCE Chemistry Question Thread
« Reply #927 on: May 25, 2014, 04:59:23 pm »
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They can give you other kinds of alcohols; not common though. Primary alcohols are most common in these reactions.
How would I write the semi-structural formula of an ester formed with a more complex alkanol? Could you please give me an example? Thank you :)
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Scooby

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Re: VCE Chemistry Question Thread
« Reply #928 on: May 25, 2014, 11:34:47 pm »
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A few questions to ask you geniuses!  ;D
  • Acetaldehyde (CH3CHO) to Ethanoic Acid, what type of reaction would this be?
  • How will this accumulation affect glycolysis and the pathways that produce CO2? Note that ethanol consumption leads to an accumulation of NADH.

It's oxidation. Ethanol is metabolised in the liver, which involves it first being converted to acetaldehyde, which is converted to ethanoic acid, which is converted to acetyl Co-A. As ethanol is metabolised, NAD+ is consumed and converted to NADH. Since NAD+ is required for glycolysis, the rate at which glycolysis occurs would reduce if NAD+ is depleted (NAD+ is essentially a limiting reactant).
 

 
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lzxnl

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Re: VCE Chemistry Question Thread
« Reply #929 on: May 25, 2014, 11:59:45 pm »
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A few questions to ask you geniuses!  ;D
  • Acetaldehyde (CH3CHO) to Ethanoic Acid, what type of reaction would this be?
  • How will this accumulation affect glycolysis and the pathways that produce CO2? Note that ethanol consumption leads to an accumulation of NADH.

 

 

 

This isn't a question in the scope of the 3/4 chem course btw :P
but any interested bio students are free to read Scooby's answer above
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