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Topic: Concentration in solution  (Read 5405 times)

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Offline curlylocks

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Concentration in solution
« on: March 06, 2008, 10:35:29 AM »
Hi Everyone,

I'm a bit stuck with a question - any help would be great.

If you have a given solution with units in ppm of ions, how do you estimate the HCO3- concentration?

Do I need to convert the ppm of the ions to moles?
Not really sure where to start :(


Offline Arkcon

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Re: Concentration in solution
« Reply #1 on: March 06, 2008, 10:40:42 AM »
Do I need to convert the ppm of the ions to moles?

If you need molar concentration for later steps then yes, you do need to convert the ppm concentration you've been given into molar concentration.  Do you know the definition of ppm?
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline curlylocks

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Re: Concentration in solution
« Reply #2 on: March 06, 2008, 10:45:39 AM »
Hi,

Yes it's parts per million and I know how to convert it, I'm just not sure if it needs to be in moles.

I have been given the concentration of different ions in a solution in ppm and have been asked to estimate the bicarbonate concentration of the solution.


Offline ARGOS++

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Re: Concentration in solution
« Reply #3 on: March 06, 2008, 10:51:45 AM »

Dear CurlyLocks;

In this case most prefer Moles per liter ( = molar).

You may  need the “Reaction” and its “Stoichiometry” depending from which Ion you  start.

Good Luck!
                    ARGOS++


Offline Borek

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Re: Concentration in solution
« Reply #4 on: March 06, 2008, 11:07:44 AM »
ppm is not precisely defined and it can mean different things depending on the circumstances. It can be a molecule per 106 molecules, it can be mg per kg, it can be μL per L. I suppose your ppm is mg per kg of solution.

What ions are present in the solution?
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline enahs

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Re: Concentration in solution
« Reply #5 on: March 06, 2008, 07:14:30 PM »
I hate PPM, as Borek pointed out there are many things involved.

Also, people seem to neglect the correct density when calculating PPM; except not always. I always have doubts when I see a PPM reported in some research paper.


I just thought I would mention how much I hate Parts Per, notation.

Offline ARGOS++

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Re: Concentration in solution
« Reply #6 on: March 06, 2008, 07:23:01 PM »

Dear CurlyLocks;

Don’t fear!,  –   Please! - show us your Question and Values, so we can try to help you.

It’s maybe not so hard as you see it at the moment.

Good Luck!
                    ARGOS++


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