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Topic: Chemistry concentration question  (Read 2725 times)

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Offline Gweedo8

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Chemistry concentration question
« on: July 01, 2009, 07:12:21 PM »

I was told to prepare some standard for a chemistry lab and here where the instructions:

Obtain a solution of known phosphate concentration. In this lab we will use (1.e-002M) potassium dihydrogen phosphate, KH2PO4. Note the concentration on your data sheet.
Pipet 0.50mL of the standard phosphate solution into a 100mL volumetric flask. Using a graduated cylinder, add 10.0mL of the ammonium molybdate solution to the flask. Then dilute to the mark with distilled water. Make sure you label this volumetric with the concentration of phosphate. (McVc=MdVd) Do this by choosing label from the menu (or right clicking)

Where
Mc = concentration of the original standard phosphate solution.
Vc = volume of concentrated standard phosphate solution TRANSFERRED to the volumetric.
Md = new diluted concentration.
Vd = total volume of the diluted solution.

The Part I do not understand is filling in the McVc=MdVd.

Here are my guesses on some but I am not 100% sure and could use some help:

Mc
Vc
Md=.5ml
Vd=100ml

Offline JGK

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Re: Chemistry concentration question
« Reply #1 on: July 01, 2009, 07:17:57 PM »
I'm getting a real sense of deja vu with your posts (and not for the first time)

http://www.chemicalforums.com/index.php?topic=34349.0
Experience is something you don't get until just after you need it.

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