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### Topic: Effect of Dilution on Molar and Mass concentration  (Read 5552 times)

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#### ziagemini

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##### Effect of Dilution on Molar and Mass concentration
« on: August 02, 2012, 06:08:18 AM »
Hello All,

What is the effect of dilution on molar and mass concentration. Or how precisly we can calculate the original concentration from diluted one. E.g. i take 1gram of sample(sludge), and dilute it with 20g of water(mass-mass), then i find the ammonium concentration using a photometer and got value of 210 mg/L how much ammonium is present in actual sample.

Hope i asked the right question. Hope to have a positive response. Thanks for the help.

Regards!

#### sjb

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##### Re: Effect of Dilution on Molar and Mass concentration
« Reply #1 on: August 02, 2012, 06:18:07 AM »
Hello All,

What is the effect of dilution on molar and mass concentration. Or how precisly we can calculate the original concentration from diluted one. E.g. i take 1gram of sample(sludge), and dilute it with 20g of water(mass-mass), then i find the ammonium concentration using a photometer and got value of 210 mg/L how much ammonium is present in actual sample.

Hope i asked the right question. Hope to have a positive response. Thanks for the help.

Regards!

Convert the 21g into a volume, then you can see how much sludge is in your diluted sample. To see how much was in the sludge, you may need to confirm if there was any in the water you added as a dilutant.

#### AWK

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##### Re: Effect of Dilution on Molar and Mass concentration
« Reply #2 on: August 02, 2012, 06:31:08 AM »
You may safely assume your diluted solution shows the same density as pure water and from this approximation calculations of mass content (mass percentage, ppm) of your sample is quite easy. For molar concentration of your sample the density of your sample is rather needed ( or volume of 1 g of sample - for dilution of sample with water assume additivity of volumes).
AWK

#### ziagemini

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##### Re: Effect of Dilution on Molar and Mass concentration
« Reply #3 on: August 02, 2012, 07:26:07 AM »
"You may safely assume your diluted solution shows the same density as pure water and from this approximation calculations of mass content (mass percentage, ppm) of your sample is quite easy"

I don't know anything about this. Can you please elaborate? Or is there any book or article refrence where such thing is being explained.

Thanks for the help

#### AWK

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##### Re: Effect of Dilution on Molar and Mass concentration
« Reply #4 on: August 02, 2012, 09:26:26 AM »
You need calculate mass balance (unknown mass of ammonia in sample = mass of ammonia in dilute solution - taking into account aproximation mass of solution = volume of diluted solution).
AWK