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Topic: Analytical method  (Read 3591 times)

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Offline XHNO20

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Analytical method
« on: February 27, 2011, 11:44:19 PM »
We have 12 chemicals that we have to identify only by mixing them. We're not given any extra chemicals, litmus paper...just the 12 unlabeled chemicals! I get the general idea, but I am having trouble coming up with a good procedure to take into the lab, and be effective.

Thanks for the help if you can give it!

Here are the chemicals:
6M HCl
3M H2SO4
6M NaOH
6M NH4OH
0.1M Cu(NO3)2
0.1 M Ba(NO3)2
0.1 M AgNO3
0.1 M Pb(NO3)2
0.1 M NiCl2
0.1 M FeCl3
0.1 M K2CrO4
0.1 M Na2CO3

Offline rabolisk

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Re: Analytical method
« Reply #1 on: February 28, 2011, 12:39:55 AM »
I would come up with a list of insoluble salts that could possibly precipitate out when you mix two of these solutions.

Offline Borek

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Re: Analytical method
« Reply #2 on: February 28, 2011, 03:56:44 AM »
To make things easier, some will be obvious at first sight.
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Offline fmhaque

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Re: Analytical method
« Reply #3 on: March 01, 2011, 07:49:07 PM »
I'm also in the same lab class and I devised a plan for this experiment.

We should be able to identify 5 through smell/sight.

NH4OH: windex-cleaner smell
Cu(NO3)2: light blue
NiCl2: translucent light green
FeCl3: gold yellow
K2CrO4: bright yellow

HCl and H2SO4 are the acids which can be detected by smell.
To identify between the two acids, HCl will turn a bright orange/yellow in nitrates.

Addition of acid to Na2CO3 will cause the solution to bubble.

Acid + NaOH --> heat

AgNO3 + CrO4 --> copper/brown
Pb(NO3)2 + CrO4 --> saturated yellow
Ba(NO3)2 + CrO4 --> light yellow

Offline Borek

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Re: Analytical method
« Reply #4 on: March 02, 2011, 03:52:54 AM »
HCl and H2SO4 are the acids which can be detected by smell.
To identify between the two acids, HCl will turn a bright orange/yellow in nitrates.

You need concentrated solutions for that.
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