In chemistry, the process of determining the precise concentration (molarity) of a solution is known as standardization. One of the most important preconditions for reliable and transparent titration determination is the so-called titer standardization/determination of the volumetric solution used for the titration.
In the titration procedure, the titrant is usually added to a known quantity of analyte (the unknown solution) from a burette until the reaction is complete. The concentration of the unknown can be determined by knowing the volume of titrant added. An indicator is often used to indicate the endpoint, or equivalence point, of the reaction.
Why is there a need to standardize the NaOH solution?
To find out the exact concentration (molarity/normality) of the prepared NaOH solution, it needs to be standardized. Unfortunately, sodium hydroxide is not a good primary standard. Since solid NaOH is highly hygroscopic, it cannot be weighed precisely. It absorbs carbon dioxide (CO2) from the air, forming sodium carbonate and lowering the amount of NaOH.
So we'll need to determine the exact concentration of the prepared NaOH solution that has the approximate concentration. The concentration of NaOH can be determined precisely by titrating a potassium hydrogen phthalate (KHP) sample of known mass with the prepared NaOH solution.
What does it mean to standardize a NaOH solution?
Standardization is the process of finding the exact concentration (molarity) of a solution. The molarity of a sodium hydroxide solution will be measured in the first standardization by titrating a sample of KHP with the NaOH.
Why is the standardization of NaOH necessary?
Because sodium hydroxide is hygroscopic, it absorbs moisture from the air quickly, changing its concentration.
Why standardized NaOH should be kept in a stoppered bottle?
As atmospheric carbon dioxide reacts with the stored NaOH to form carbonic acid when it comes into contact with it. As a result, the concentration of the base decreases. Therefore, sodium hydroxide must be kept in a closed bottle to avoid interaction with atmospheric carbon dioxide.
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