Buffer
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(Created page with 'A buffer by definition resists changes in the pH of a solution. A buffer must contain the chemical species for “neutralizing” added amounts of acid or [[base|…') |
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| − | A buffer by definition resists changes in the [[ | + | A buffer by definition resists changes in the [[PH|pH]] of a solution. A buffer must contain the chemical species for “neutralizing” added amounts of [[Acid|acid]] or [[Base|base]]. Generally, a buffer is a solution of a [[Weak acid|weak acid]] and its conjugate [[Base|base]] (e.g. acetic acid and sodium acetate) or a [[Weak base|weak base]] and conjugate acid (e.g. ammonia and ammonium chloride). |
| − | Buffers are most effective in the range pH = pK’a ± 1. Outside the range the concentration of either the [[ | + | Buffers are most effective in the range pH = pK’a ± 1. Outside the range the [[concentration|concentration]] of either the [[Acid|acid]] or the conjugate [[Base|base]] is too small to effectively resist the effect of added hydrogen or hydroxide ions. |
Revision as of 22:07, 27 July 2010
A buffer by definition resists changes in the pH of a solution. A buffer must contain the chemical species for “neutralizing” added amounts of acid or base. Generally, a buffer is a solution of a weak acid and its conjugate base (e.g. acetic acid and sodium acetate) or a weak base and conjugate acid (e.g. ammonia and ammonium chloride).
Buffers are most effective in the range pH = pK’a ± 1. Outside the range the concentration of either the acid or the conjugate base is too small to effectively resist the effect of added hydrogen or hydroxide ions.
