Standardization of Solutions with Primary Standards

Categories: Chemistry

Essay, Pages 3 (532 words)

Views

1. Purpose

The purpose of this experiment is to demonstrate the process of standardization using a primary standard and to highlight its applications in environmental chemical analysis.

2. Procedure

The experiment was conducted following these steps:

Cleaned all equipment with distilled water.
Poured 500 ml of distilled water into a Florence flask and added 1.1 ml of concentrated solution. The flask was then filled with distilled water up to 1 L.
Added 0.1188 mg of HgO (primary standard) to 25 ml of distilled water in an Erlenmeyer flask, ensuring no loss of HgO by pouring 75 ml of water over aluminum foil covering the surface.

Don't use plagiarized sources. Get your custom paper on

“ Standardization of Solutions with Primary Standards ”
Get high-quality paper
NEW! smart matching with writer
Heated the mixture to 30°C and used a stirrer to agitate it.
After a few minutes, added a full spoon of KI into the mixture.
Transferred 49.8 ml of the solution into a burette.
Added 6-7 drops of methyl-red indicator to the primary standard solution.
Started titration of the primary standard solution with the solution, observing the color change from yellow to pink when 33.1 ml of solution was used, and stopped the titration at the endpoint.

Get quality help now

Marrie pro writer

Verified writer

Proficient in: Chemistry

5 (204)

“ She followed all my directions. It was really easy to contact her and respond very fast as well. ”

+84 relevant experts are online

Hire writer

3. Theory

Quantitative analysis techniques play a crucial role in determining the amounts of species present in a solution. Volumetric analysis, one such technique, relies on volume measurements and includes standardization as a critical component. The primary objective of standardization is to accurately determine the concentration of a solution. It is typically performed using a primary standard, which is a reference reagent with a known purity and certain properties such as resistance to oxidation and crystallization. In this experiment, Mercuric Oxide (HgO) served as the primary standard to standardize an acid solution through titration.

Titration is a quantitative process used to standardize a solution by gradually adding a primary standard solution to it. The point at which titration concludes is known as the endpoint, which may differ slightly from the theoretical equivalence point due to titration errors. Indicators are vital in titration, as they signal the endpoint by altering certain properties of the primary standard, such as color, turbidity, electrical properties, or temperature.

4. Data Analysis & Calculations

Data

1) Volume of solution used in titration: 33.1 ml

2) Molecular weight of _HgO: 216.59 g/mol

Concentration of the standardized solution:

_{Molarity (M) = Moles (mol) / Volume (L)}

_{Molarity (M) = 0.1188 mg / (0.020 moles / 1L) = 5.94 M}

5. Discussion and Conclusion

1) The use of standardized solutions in environmental chemical analysis is of paramount importance as it allows us to determine the strength, purity, and exact concentration of a solution. Employing standardized solutions helps prevent errors in experimental findings and minimizes the risk of chemical injuries.

2) It is worth considering alternative primary standards like Na₂CO₃ due to their properties, including known purity, ease of preparation, and resistance to oxidation.

3) In laboratory experiments, the elimination of errors is nearly impossible. Three main types of errors encountered are random errors, systematic errors, and gross errors. Personal errors, such as slightly underusing the primary standard, variations in heating time, and distillation frequency, were the main contributors to errors in this experiment. It was expected that errors would be relatively high due to these factors.