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# solution

molarity sloution buffer

7 replies to this topic

### #1 M.B.T

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Posted 19 November 2014 - 12:34 PM

Hi everyone,

I need to ask something but I apology in advance if this kind of question was asked here before.

I need to make 10 ml of 5 X Loading buffer which required final concentration 250mM Tris HCL. I have 1 M Tis HCL stoke.

Using C 1 V1 = C2  V2 equation . I found out I need to take 2.5 ml of  1 M Tis HCL stoke to have 250 mM final concentration.

I am wondering what I did it right or I can not dilute molarity and I have to make a stock solution with 250 mM.

thank you

### #2 bob1

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Posted 19 November 2014 - 12:53 PM

The "m" part of mMol/l is "milli" - it means a thousandth (e.g. millimetre, where it means a thousandth of a metre). So... how many thousandths would make up 1 M... so what about 250 mM, how many Mol/l is this?

### #3 M.B.T

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Posted 19 November 2014 - 01:07 PM

A thousand mM will give a M.

What about 250 mM, how many Mol/l is this?  Is this 0.25 M/L

What I try to ask was could I dilute a stock solution with certain molarity (e.g 1 M) to make another solution with another molarity (e.g 250 mM) or I can not dilute the molarity?

Thanks

### #4 Wan2Know

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Posted 19 November 2014 - 01:16 PM

Hi,
250mM=0,25M
1Mx?=0,25Mx10ml, C1=2,5ml you should take from your stock and add 8,5ml of water to obtain 10ml of Tris HCl at 250mM or 0,25M.
Other members should confirm that.

### #5 M.B.T

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Posted 19 November 2014 - 03:20 PM

Perfect, thank u

### #6 phage434

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Posted 19 November 2014 - 03:24 PM

Except you should add 7.5 ml of water, not 8.5 ml, since you want the final volume to be 10 ml.

### #7 bob1

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Posted 19 November 2014 - 06:20 PM

A thousand mM will give a M.

What about 250 mM, how many Mol/l is this?  Is this 0.25 M/L

What I try to ask was could I dilute a stock solution with certain molarity (e.g 1 M) to make another solution with another molarity (e.g 250 mM) or I can not dilute the molarity?

Thanks

You can only dilute from a more concentrated stock to a more dilute... What I was trying to get you to see is that 250 mmol/l or 0.25 mol/l is a quarter of 1 mol/l... and a quarter of 10 is...2.5!

### #8 Wan2Know

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Posted 20 November 2014 - 01:06 AM

Hi,

Sorry for my mistake, the simplest calculation was wrong. 7,5ml and not 8,5ml ;-)