STANDARDISATION OF 0.1 M HCl
Borax dissolves slowly in water at room temperature. Why do we not use a stirring
rod to mix the solution and speed up this stage of the experiment?
To be honest about it I don't know; however, my best educated guess is that the glass in beakers/stirring rods etc are borosilicate glass and small amounts of glass could be abraded with vigorous stirring and that would affect the standardization.
To understand why a stirring rod is not used to speed up the dissolution of Borax in water at room temperature, we need to consider the properties of Borax and the process of dissolving.
Borax is a compound that consists of large crystals, and its dissolution in water occurs through a process called solvation. During solvation, water molecules surround the individual ions or molecules of the solute (in this case, Borax) and separate them from their crystal lattice. This process is essential for the dissolution to occur.
Using a stirring rod to mix the solution may seem like a logical way to speed up the process, but it may not be effective for a few reasons:
1. Crystal Lattice Breakage: Stirring the solution forcefully may cause the Borax crystals to break apart, generating smaller particles. These smaller particles will dissolve faster, but they may lead to inaccuracies in the experiment as they increase the surface area available for reaction. This could affect the concentration and the outcome of the experiment.
2. Saturation: Stirring the solution vigorously might lead to the oversaturation of the solution with Borax. Oversaturation occurs when the concentration of the solute exceeds its solubility limit, resulting in the formation of a solid precipitate. This would hinder the complete dissolution of Borax.
3. Temperature Dependency: The solubility of many substances, including Borax, is temperature-dependent. In this case, the solubility of Borax increases with higher temperatures. Simply stirring the solution will not change the temperature, and thus will not significantly impact the rate of dissolution.
In conclusion, the slow dissolution of Borax in water at room temperature is a natural process that should not be artificially sped up using a stirring rod. The solvation process takes time, and using a stirring rod may lead to unintended side effects that could affect the accuracy of the experiment.