This allows for quantitative analysis of the concentration of an unknown acid or base solution. It makes use of the naturalization reaction that occurs between acids and bases and the knowledge of how acids and bases will react if their formulas are known. Acid-base titration can also be used to find percent purity of chemicals. When a weak acid reacts with a weak base, the equivalence point solution will be basic if the base is stronger and acidic if the acid is stronger.
If both are of equal strength, then the equivalence pH will be neutral.
However, weak acids are not often titrated against weak bases because he color change shown with the indicator is often quick, and therefore very difficult for the observer to see the change of color. The point at which the indicator changes color is called the end point. A suitable indicator should be chosen, preferably one that will experience a change in color (an end point) close to the equivalence point of the reaction.
First, the burette should be rinsed with the standard solution, the pipette with the unknown solution, and the conical flask with distilled water.
Secondly, a known volume of the unknown concentration solution should be taken with the pipette and placed into the Monica flask, along with a small amount of the indicator chosen. The known solution should then be allowed out of the burette, into the conical flask. At this stage we want a rough estimate of the amount of this solution it took to neutralize the unknown solution.
The solution should be let out of the burette until the indicator changes color and the value on the burette should be recorded.
This is the first (or rough) titer and should be discussed from any calculations. At least three more titration should be performed, this time more accurately, taking into account roughly where the end point will occur. The initial ND final readings on the burette (prior to starting the titration and at the end point, respectively) should be recorded. Subtracting the initial volume from the final volume will yield the amount of iterant used to reach the endpoint. The end point is reached when the indicator just changes color permanently.