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Topic: what is the molarity of water?  (Read 22759 times)

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Offline doubt

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what is the molarity of water?
« on: May 16, 2007, 02:53:01 AM »
My Question is

"What is the molarity of Water?"



can you please explain me the answer clearly with an small explanation

May I request you to be clear in the answer please?

since i'm not an chemical student...but wish to know the molarity of water

please..

please please ..explain with a small example..


thank you very very much in advance.

Offline Borek

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Re: what is the molarity of water?
« Reply #1 on: May 16, 2007, 03:04:56 AM »
Simply start with molarity definition - all you have to do is to plug numbers ;)
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Offline Dolphinsiu

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Re: what is the molarity of water?
« Reply #2 on: May 16, 2007, 03:18:40 AM »
Molarity means concentration.

For example, molarity of NaCl solution = concentration of NaCl solution

Offline AWK

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Re: what is the molarity of water?
« Reply #3 on: May 16, 2007, 03:33:23 AM »
How many moles of H2O are in 1 liter of water?
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Offline english

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Re: what is the molarity of water?
« Reply #4 on: May 16, 2007, 03:00:18 PM »
Think about water's density, and what the units signify.  The answer lies there.

Offline DevaDevil

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Re: what is the molarity of water?
« Reply #5 on: May 16, 2007, 05:01:49 PM »
well, the molarity of water is a tricky one, as usually we take water as solvent and are interested only in the molarity of the solute.

Basic explanation is as Borek referred to:
Molarity = number of moles per unit volume.

Now with the molarity of water you have to go to the basics:
-The density (r, Temperature dependant!) will give you the number of grams per dm3
-The molar mass (M, in g/mol) will allow you to calculate mass (grams) into moles.

So: r / M
will give you number of moles/dm3 = molarity

Offline AWK

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Re: what is the molarity of water?
« Reply #6 on: May 17, 2007, 01:13:04 AM »
Think about water's density, and what the units signify.  The answer lies there.
For molarity, density is not needed
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Offline english

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Re: what is the molarity of water?
« Reply #7 on: May 17, 2007, 10:07:18 AM »
Think about water's density, and what the units signify.  The answer lies there.
For molarity, density is not needed

Yes but it's easier.  If you have x L of water and we assume that its density is approx. 1 g/mL, or 1 kg/L, then you know how many grams of water are in x L of water. 

Denisty of water is such a commonality that I see it as the easiest way.

Offline ARGOS++

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Re: what is the molarity of water?
« Reply #8 on: May 18, 2007, 11:58:01 AM »

Dear GWK,  Dear All,

Sorry, but now I believe, that something went wrong!!

DONNOT intermix MolaLity with MolaRity, NEVER !!!

MolaLity is a MASS-Conzentration!
MolaRity is a VOLUME-Conzentration!
That means, that MolaRity MUSST very strongly depend on the Density of the Solvent you use.

But for theThumb-Rule” it is allowed to set the Density of Water to 1.00 g/cm3,
what results in the simple Division of: 1000g / “MW of Water”,
with the “Schnaps-Zahl” of  55.55  !!!

Good Luck!
                    ARGOS++


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