Answer:

PURPOSE

Standardization process aims to check if a solution contains the right amount of reagent or compound it claims to have. A variety of factors could influence inaccurate amount of substance in the solution, e.g. hydroscopic property that hinders from accurate weighing. Standardization is done for reagents that are not of high purity and cannot be used as a reference material for volumetric and mass titrimetry. The solution using such reagents cannot be used as reference material to analyze other reagents unless the solution be standardized. The process also allows calibration or adjustment in computation just in case it does not contain the exact amount—so that the standardized solution may be useful as reagent in your laboratory.

PRE-REQUISITES

To standardize a reagent, here are background information about the reagent needed:

• A primary standard must be identified for the specific reagent. Here are examples of primary standards:

1. Arsenic trioxide (As₂O₃) - used to prepare sodium arsenite solution to standardize sodium periodate (NaIO₃)
2. Potassium bromate (KBrO₃) - to standardize sodium thiosulfate (Na₂S₂O₃)
3. Potassium hydrogen phthalate (KHC₈H₄O₃) or KHP - to standardize aqueous base and perchloric acid in acetic acid
4. Potassium dichromate (K₂Cr₂O₇) - to standardize sodium thiosulfate

• If the reagent desired to be standardized does not correspond to any primary standard mentioned above, a secondary standard can be identified for the reagent. Secondary standard is a solution standardized using a primary standard and can be used to standardize another reagent. For example, hydrochloric acid (HCl) does not correspond to any primary standard. A 1 M NaOH can be standardized using a primary standard KHP. The standardized 1M NaOH can be used as secondary standard for HCl.
• Other properties of the reagent should also be identified, if the reaction would be in acid-base titrations, complexation titration, reduction-oxidation (redox) titration, or precipitation titrations.

CONCLUSION

An experimental molarity of the reagent can be obtained. The precision in trials could also be calculated to assess if the experimental molarity obtained is reliable.

Resources:

1) https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Book%3A_Analytical_Chemistry_2.1_(Harvey)/09%3A_Titrimetric_Methods

2) https://www.extension.iastate.edu/wine/preparing-standard-sodium-hydroxide-solution

3) https://www.cerritos.edu/chemistry/_includes/docs/Chem_111/Lab/Exp%2012%20-A%20Standardization%20of%20NaOH%20F%2008.pdf

4) https://books.google.com.ph/books?id=Stw7DQAAQBAJ&printsec=frontcover&dq=quantitative+chemistry+titrations&hl=en&sa=X&ved=2ahUKEwjujNOTsMPtAhWSv5QKHSh-BWwQ6AEwAHoECAMQAg#v=onepage&q=quantitative%20chemistry%20titrations&f=false

Step-by-step explanation

Please visit the references to see illustrations and more examples. You may also read Chapter 1 of this book: Quantitative Analytical Analysis. https://books.google.com.ph/books?id=Stw7DQAAQBAJ&printsec=frontcover&dq=quantitative+chemistry+titrations&hl=en&sa=X&ved=2ahUKEwjujNOTsMPtAhWSv5QKHSh-BWwQ6AEwAHoECAMQAg#v=onepage&q=quantitative%20chemistry%20titrations&f=false