# Mole and Millimole

Discussion in 'Community Submitted Guides & Links' started by hanadr, May 3, 2009.

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Introducing “The Mole and his smaller cousin Millimole.
When I taught elementary chemistry, some of my pupils had trouble with a concept called the “mole”. I found it useful and not at all difficult, but that’s me. I can do percentages too.
When dealing with small molecules, it’s easy. Most people remember from school science that water molecules have the symbol H2O. That means that every water molecule consists of 2 hydrogen atoms chemically combined with an oxygen atom.
The relative weight of an atom is determined by comparison with a carbon atom a carbon RAM = 12 On that scale H=1 and O = 16, thus a water molecule weighs 18 on the RAM scale
Using the same scale Salt ~ Sodium chloride~ Na Cl RAM~23 + 35.5 +58.5
And glucose C6 H12 O6~ 72+12+96=180.
If you weigh out the RAM equivalent in grams of any substance the quantity you will have will be a “mole” and each mole of any element or compound contains Avogadro’s number(6.02 X 10 23 )of atoms or molecules. That’s 6.02,000,000,000,000,000,000,000
I find problems doing the sums for haemoglobin, since there are several different kinds
One formula for one of the various chains of Haemoglobin is
C738H1166N812O203S2Fe
A mole of this stuff weighs 24758g, which is a mole
Millimole is 1/1000 of a mole
Hence 0.18g glucose or 0.059g salt, or 0.018g water or 24.758g of the kind of haemoglobin chain I calculated
I haven’t found out yet whether it’s millimoles of Glycosylated haemoglobin, of whichever chain in What? Unglycosylsted haemoglobin? Whole blood? Which.? It won’t make total sense until I find out. And which kinds of haemoglobin chains?
If the test stays the same, it’s Glycosylated haemoglobin as a proportion of total haemoglobin and there wasn’t really any point in confusing me and making me do all this maths.

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2. ### sugarless sue · Master

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Hana ,I'm going to move this to the Stickies forum so that it does not get 'lost'.

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Ok Sue if you could add apicture of a mole, that would be lovely. I had one on the original Word document, but it didn't come over.

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4. ### IanD Type 2 · Well-Known Member

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As Tom Lehrer warned before his "Elements Song" there will be a test ... :wink:

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5. ### IanD Type 2 · Well-Known Member

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Hana - why the decimal pt after the 6 :?: It makes the Avogadro number (6.02x10^23) 6.02.

We ARE paying attention :twisted:

And when will you update your profile pic on FACEBOOK :?: That tiny baby is a toddler now.

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6. ### phoenix Type 1 · Expert

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HbA1c results traceable to the IFCC
reference method derived will be expressed
as mmol per mol of unglycated
haemoglobin

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7. ### Grumpy · Well-Known Member

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Will there be an English translation of this available soon, please? Although I understood the bit about the photograph...
This just goes to show how right I was to give up chemistry after the third form. :mrgreen:

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8. ### cugila · Master

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Hi Grumps.

One little snippet that might explain something ( Avogadro's ) mentioned here. :?

Avogadro's Number is 6.0221415 × 10 to the power of 23
This is the number of atoms in one mole of a substance.

I'm not sure how it could be useful in daily life, but its scientific significance is that it is the number of particles (atoms or molecules) in one gram-molecular-weight of that substance.

Chemists use Avogadro's number every day. It is a very valuable number for a chemist to know how to use. Hi hanadr. Am I doing alright so far ?

Not sure I am going to try and explain anything else. I need a lie down. :? :? :?

Ken.

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9. ### kegstore · Well-Known Member

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With great respect to all the chemists out there, but most of us aren't scientists or mathematicians. I'm sure it's all very clever, but I'm really not interested in how the number is derived, but instead the actual number and what it means to me and the lay diabetic. What a shame we have another scale to deal with and get used to, although the newly-diagnosed will have no problem at all. :?

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