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# Molar Calculation

Molar calculation

### #1 uday

uday

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Posted 19 November 2012 - 11:15 AM

What a shame ! I got stuck in molar calculations.

Can anybody show how to do the math for making a 100mM, 100uL solution of X from the commercial available X solution of 96% ?

The details of the X are as follows.
96% assay
MW 222.37g/mol
density 0.879 g/ml

i.e. How much of commercially available X to be added ?

### #2 pito

pito

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Posted 19 November 2012 - 11:47 AM

100mM= 0,1M meaning: 0,1mol per liter.
Because you need 100µl, you need not 0,1 mol (thats for 1liter) but 0,1x10^-4 mol or 1x10^-5 mol

Since you have 223,37gram per mol, you need not 223,37 grams but 223,37 x 10^-5 grams.

and the solution s 96%, so 223,37grams is only 96%, so 100% = ? grams..
If you know this, you know how much ml you need to take from the stock.

Redo the math, check it yourself.
(its possible I made an error somewhere, buts its basic math)
Do you understand it?

Edited by pito, 19 November 2012 - 11:48 AM.

If you don't know it, then ask it! Better to ask and look foolish to some then not ask and stay stupid.