Buffer Solutions

• Buffer solutions are comprised of either a weak acid and its salt or a weak base and the salt of that particular acid or base. Buffer solutions withstand changes in pH when minor amounts of an acid or an alkali are added to it. They are used as a means of maintaining pH at an invariable value in an assortment of chemical applications.
  
  

Functions

• A buffer solution must have elements that will dispatch any hydrogen ions or hydroxide ions which may be added. Without these ingredients, the pH will change. Acidic and alkaline buffer solutions achieve this in different ways.
  
  

Acidic and Alkaline Buffer Solutions

• Acidic buffer solutions have a pH less than 7. They are commonly made with a weak acid and a sodium salt. Phosphate buffer solutions are particularly useful in biological applications. Because it has multiple dissociation constants, phosphate buffers can be prepared at all three pHs, which are 2.15, 6.86 and 12.32. Changing the ratio of acid to salt or applying a different acid and one of its salts is what alters the pH of the buffer solution. Alkaline buffer solutions have a pH greater than 7. These are typically made with a weak base and one of its salts. Again, changing the concentrations will not alter the pH as long as they remain equal.
  
  

Le Chatelier's Principle

• Le Chatelier's Principle explains that changes imposed on a solution in equilibrium occur with changes in concentration, pressure or temperature. This equation helps determine what effect increasing or decreasing a solution's component will have on the solution as it adjusts to a new equilibrium and counteracts the change that has been made. Le Chatelier's Principle is referred to when creating buffer solutions to predetermine the solution's outcome and success.
  
  

Blood

• Many organisms flourish only in a comparatively modest pH range utilizing blood as their natural buffer solution. Buffers dissolved within the blood keep the blood's pH relatively constant, with assistance from other organs. For example, the kidneys help remove excess chemicals from the blood to prevent excessive buildup and kidney failure. The lungs help counteract pH-lowering activities, such as exercise, by withdrawing carbon dioxide, a component of the principal pH buffer in blood.