Answer to Question #78949 in Inorganic Chemistry for ray

Question

When performing acid-base titration, one should first?

Answer 1

An acid–base titration is the determination of the concentration of an acid or base by exactly neutralizing the acid or base with an acid or base of known concentration. Before starting the titration a suitable pH indicator must be chosen

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 conical 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 colour and the value on the burette should be recorded. This is the first titration volume and should be excluded from any calculation.

At least three more titrations should be performed, this time more accurately, taking into account roughly where the end point will occur. The initial and final readings on the burette should be recorded. Subtracting the initial volume from the final volume will yield the amount of titrant used to reach the end point. The end point is reached when the indicator just changes colour permanently.