Author Topic: CHEM AND BIO HELP AND TIPS HERE  (Read 351129 times)

elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2520 on: June 05, 2010, 09:52:46 am »
need help with s09 q5b...

no problem.. ;)
anyways

the vol. of phosphate soln used in cm3 is half the height of the ppt in mm
also at 8cm3 all the soln is used up. tht is because adding more does not increase the height of the ppt meaning there was no further reaction on adding more.
also the formula is T3(PO4)2-----because

u take it as 12cm3 of T nitrate react with 8cm3 of sodium phosphate (thts wen all the reactants r used up)
so.....12:8...simplify it
12:8
6:4
3:2
and therefore u get T3(PO4)2

nid404

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2521 on: June 05, 2010, 09:55:42 am »
This is AN OLDDDDDD paper with a teacher MS that says Hydrogen and Chlorine are produced.

Ohkay.

I just went through my collins text

It says

In an aqueous solution...both positive ions will go to the cathose but only the H+ ion is discharged as H2
similarly both negative ions go to the anode but only the Cl- ion is discharged as Cl2


elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2522 on: June 05, 2010, 09:57:37 am »
So when they say just aqueous we assume its concentrated and hence OH- ions WILL NOT be discharged at the anode ?

Instead Cl- will discharge ?

nid404

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2523 on: June 05, 2010, 10:00:35 am »
That's what the book says  :-\

If you find a similar question, it'll be easier to compare and check if they ALWAYS mean aqueous=conc

elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2524 on: June 05, 2010, 10:01:50 am »
That's what the book says  :-\

If you find a similar question, it'll be easier to compare and check if they ALWAYS mean aqueous=conc

in 2009 there was a similar question but they were specific about it being CONCENTRATED aqueous.

Thanks Nid ;)

+rep

nid404

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2525 on: June 05, 2010, 10:03:11 am »
Not a problem  :)

Offline $H00t!N& $t@r

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2526 on: June 05, 2010, 10:04:05 am »
"If A equals success, then the formula is:
A=X+Y+Z, X is work. Y is play. Z is keep your mouth shut"- Albert Einstein

Offline Raywin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2527 on: June 05, 2010, 10:31:20 am »
Hey guys, another doubt, what are macromolecules?  Are they the same as polymers??  ???  ???  ??? And also can acidified potassium manganate (vii) be decolourised by an alkene? Thanks once again..  :D :D 
;D

Offline Meticulous

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2528 on: June 05, 2010, 10:36:12 am »
Hey guys, another doubt, what are macromolecules?  Are they the same as polymers??  ???  ???  ??? And also can acidified potassium manganate (vii) be decolourised by an alkene? Thanks once again..  :D :D 

Macromolecules are substances with large molecular structure; like silicon, diamond, etc..

And yes, potassium permanganate is decolorized when added to an alkene. (purple-->colourless)

Offline Raywin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2529 on: June 05, 2010, 10:39:12 am »
Macromolecules are substances with large molecular structure; like silicon, diamond, etc..

And yes, potassium permanganate is decolorized when added to an alkene. (purple-->colourless)

Oh kay, so macromolecules have nothin to do with polymers?? and thank you..  ;D
;D

elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2530 on: June 05, 2010, 10:41:07 am »
Oh kay, so macromolecules have nothin to do with polymers?? and thank you..  ;D

Macromolecules are defined as made up of many smaller units- monomers.

So polymers ARE macromolecules.

What AF told you is ANOTHER definition of macromolecue.

Offline Raywin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2531 on: June 05, 2010, 10:42:21 am »
Macromolecules are defined as made up of many smaller units- monomers.

So polymers ARE macromolecules.

What AF told you is ANOTHER definition of macromolecue.

Oh ryte, got it, thanks you Ari and AF..  :D  :D  ;D
;D

Offline Meticulous

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2532 on: June 05, 2010, 10:42:51 am »
Not all macromolecules are polymers.

But all polymers are macromolecules

elemis

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2533 on: June 05, 2010, 10:44:25 am »
Not all macromolecules are polymers.

But all polymers are macromolecules

Couldn't have said it better myself. +rep ;)

Offline Meticulous

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2534 on: June 05, 2010, 10:49:30 am »
Thanks ari.