Chemical Forums

Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: JennLyn6 on March 21, 2004, 05:22:45 PM

Title: how do you create a buffer system?
Post by: JennLyn6 on March 21, 2004, 05:22:45 PM

how would you go about to create a buffer system?

Edit: edited title for better indexing. Mitch

Title: Re:one more please
Post by: Mitch on March 21, 2004, 07:30:46 PM

Do you want an equation or just a rough description?

Title: Re:one more please
Post by: Donaldson Tan on March 21, 2004, 11:31:12 PM

a buffer can be created by mixing a weak acid with a strong base, or a strong acid with a weak base. The later is not favoured, cuz typically the working range of most pH indicators will not fall into the buffer system's range  ;)

Title: Re:one more please
Post by: JennLyn6 on March 22, 2004, 08:14:58 AM

thank you for your reply, i would like a description please

Title: Re:one more please
Post by: GCT on March 22, 2004, 07:55:04 PM

First you need to know the pH of the system you wish to create.  Find a conjugate base/acid which (dually weak) with a suitable pKa, you should easily be able to find a list of these in a standard chem book.  Use the henderson hasselbach equation (look it up if you do not know what I am talking about) to find the relative concentration of buffer acid and base.