Chemical Forums
Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: neil.smif on May 15, 2008, 10:40:20 AM
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*delete me*!!
I need to make 500ml of 250millimoles of NaAc buffer. And pH to 5 with 1M of HCL.
(The Fw of the NaAc is 82.03g)
How do I do this? I cant change the volume, nor the molarity of HCL.
It seems like I'm adding too much HCL, which would make the buffer weak, and affect the total weight per volume
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*delete me*!!
I need to make 500ml of 250millimoles of NaAc buffer. And pH to 5 with 1M of HCL.
(The Fw of the NaAc is 82.03g)
How do I do this? I cant change the volume, nor the molarity of HCL.
It seems like I'm adding too much HCL, which would make the buffer weak, and affect the total weight per volume
4.1 g Na Ac, dissolve in ~450 mL water adjust to pH 5 with the acid, make up to volume with water, job done.
One question, why pH with HCl ? HAc would have been my first choice.
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Thanks for that. I would of also used HAc, however the people I am doing this for prefer to use HCL for some strange reason in low molarity!
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4.1 g Na Ac
No. 250 mmol, not 100 mmol. 10.25 g.
neil.smif: there are programs to calculate buffers for you. See my signature ;)
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Being a biologist, I dont really get to do much chemistry, so this all all new to me. Is there a simple equation that can be used to work this out? Thanks in Adnvance.
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It is called Henderson-Hasselbalch equation (http://www.chembuddy.com/?left=pH-calculation&right=pH-buffers-henderson-hasselbalch). But it not as straightforward as you would like it.
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Thanks again for all your help ;D
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I need to dissolve 50% Hexadeconal in a 50% Dodecane Solution, does anyone know how this is done?
Thanks in advance.