Author Topic: Indicators  (Read 1287 times)

Offline XaM!!

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Indicators
« on: May 24, 2010, 11:32:48 am »
hey guys i need help... m havn prob with indicators in chem practicals. can anyone tell me whch indicators r used with which kind of exp?

whch indicators r used in folowng papers. plz answer all of them:
i)nov 03 ques 2 indicator?
ii)may 04 ques 1
iii)oct 05 ques 1... plz m w8in...
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Offline CHEMMASTER6000

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Re: Indicators
« Reply #1 on: May 24, 2010, 11:37:18 am »
is this edexcel papers?


Offline XaM!!

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Re: Indicators
« Reply #2 on: May 24, 2010, 11:45:28 am »
Cie
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Offline CHEMMASTER6000

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Re: Indicators
« Reply #3 on: May 24, 2010, 12:08:15 pm »
hmm, thought pracs were done. unless your refering to paper 5.
anyhow .

acid natured soln would require methyl orange which has range 3 to 4

basic nature soln would require phenotheilein which has range 8 to 10  :P

Offline XaM!!

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Re: Indicators
« Reply #4 on: May 24, 2010, 02:14:17 pm »
Thanks alot
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Offline XaM!!

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Re: Indicators
« Reply #5 on: May 24, 2010, 02:16:02 pm »
can u plz answer those pprz ques???
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Offline CHEMMASTER6000

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Re: Indicators
« Reply #6 on: May 24, 2010, 03:29:03 pm »
which papers are they? p1 p2 p3 p4 p5?

Offline XaM!!

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Re: Indicators
« Reply #7 on: May 24, 2010, 03:35:13 pm »
Dnt walk As iF u RulE da WorLd..... Walk As if U dOnT CarE wHO RuLzz It.......



Offline CHEMMASTER6000

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Re: Indicators
« Reply #8 on: May 25, 2010, 03:17:03 am »
UMM dude its passed already.  :o

Offline Chingoo

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Re: Indicators
« Reply #9 on: May 25, 2010, 09:17:25 am »
Actually, they haven't passed already. There are in total four practical papers and as far as I know, 33 has it's Physics today and 34 is yet to test for all exams.

I'm not referring to a particular practical question, but the rules for choosing an indicator are:
1) If the titration is between a weak base and strong acid, use methyl-orange/screened methyl-orange indicator.
2) If the titration if between a strong base and weak acid, use phenolphthalein indicator.
3) If the titration is between a strong base and strong acid, you can use either indicator.

I'm not sure for a weak base and weak acid, but I believe that is beyond the scope of our practicals.
All that is on earth will perish:
But will abide (forever) the Face of thy Lord--full of Majesty, Bounty & Honor.
Then which of the favors of your Lord will ye deny?


Qura'n, Chapter 55: The Beneficent, Verses 26-28

Offline XaM!!

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Re: Indicators
« Reply #10 on: May 25, 2010, 09:41:40 am »
@chingo any idea wats coming in practical? iv heard iodometry?
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Offline Chingoo

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Re: Indicators
« Reply #11 on: May 25, 2010, 09:50:41 am »
Nope, I have no idea.
All that is on earth will perish:
But will abide (forever) the Face of thy Lord--full of Majesty, Bounty & Honor.
Then which of the favors of your Lord will ye deny?


Qura'n, Chapter 55: The Beneficent, Verses 26-28

Offline XaM!!

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Re: Indicators
« Reply #12 on: May 25, 2010, 10:05:08 am »
Oh ok. :-(
Dnt walk As iF u RulE da WorLd..... Walk As if U dOnT CarE wHO RuLzz It.......



Offline chocoholic-me

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Re: Indicators
« Reply #13 on: May 25, 2010, 01:01:22 pm »
good sites for last minute revision .. i found them helpful :)

http://spark000.blogspot.com/