Asked by Tom
what is the pH range of the buffering region?
is that when ph=pKa?
is that when ph=pKa?
Answers
Answered by
DrBob222
The best buffering is when pH = pKa. The RANGE, however, generally is considered to be +/- 1 from pKa. That's the definition of buffering capacity.
Answered by
Tom
so if the pka is 4.5 the range will be from 3.5 to 5.5?
Answered by
DrBob222
You can read more about it here.
http://www.cartage.org.lb/en/themes/Sciences/Chemistry/Inorganicchemistry/AcidsBases/Acidsbasesindex/Bufferrange/Bufferrange.htm
I think the buffer capacity is associated with the buffer range. The buffer capacity is defined as the amount of acid or base that can be added without exceeding +/- 1 in pH. The buffer range is the pH range that can be experience by the solution and still act as a buffer. And that is generally +/- 1 pH unit. Yes, in your case, that would be 3.5 to 5.5. A buffer with pKa 4.5 would be expected to work very well withing that range and would not be expected to work well outside that range.
http://www.cartage.org.lb/en/themes/Sciences/Chemistry/Inorganicchemistry/AcidsBases/Acidsbasesindex/Bufferrange/Bufferrange.htm
I think the buffer capacity is associated with the buffer range. The buffer capacity is defined as the amount of acid or base that can be added without exceeding +/- 1 in pH. The buffer range is the pH range that can be experience by the solution and still act as a buffer. And that is generally +/- 1 pH unit. Yes, in your case, that would be 3.5 to 5.5. A buffer with pKa 4.5 would be expected to work very well withing that range and would not be expected to work well outside that range.