Experiment on Titration of Acids and Bases

Suppose some deionized water was left in the buret before it was filled with the oxalic acid solution you were using as a primary standard. When you perform the standardization of sodium hydroxide in Part 3, how would the excess water affect the concentration of sodium hydroxide you calculate?

If deionized water was left in the buret before filling it with the oxalic acid solution, it means that there would be a dilution of the sodium hydroxide solution during the titration. The excess water would essentially decrease the concentration of the sodium hydroxide solution.

When calculating the concentration of the sodium hydroxide solution, you would need to take into account this dilution factor. The molarity of the sodium hydroxide solution can be calculated using the formula:

Molarity of NaOH solution = (moles of oxalic acid) / (volume of sodium hydroxide solution used)

Since the sodium hydroxide solution is diluted due to the excess water, the volume of the sodium hydroxide solution used in the titration would be greater than the actual volume of sodium hydroxide. Thus, the moles of oxalic acid used in the titration would remain the same, but the volume of sodium hydroxide solution used would be larger, resulting in a lower concentration of sodium hydroxide.

To correct for this, you would need to adjust the volume of sodium hydroxide solution used in the calculation by subtracting the volume of excess water in the buret. This would give you a more accurate concentration of sodium hydroxide.

If there was excess deionized water left in the buret before filling it with the oxalic acid solution, it would indeed affect the concentration of sodium hydroxide that you calculate during the standardization process.

To understand how this excess water would affect the calculation, let's go through the process of standardizing sodium hydroxide with oxalic acid:

1. Normally, when standardizing sodium hydroxide, you would measure a known volume of the oxalic acid solution from the buret into a flask.

2. Then, you would add a few drops of a suitable indicator to the flask. The indicator changes color when the acid is neutralized by sodium hydroxide.

3. Next, you would begin adding sodium hydroxide from another buret into the flask containing the oxalic acid solution, while swirling the flask gently.

4. The sodium hydroxide is added until the indicator changes color, indicating that the acid has been completely neutralized.

5. At this point, you would read the volume of sodium hydroxide solution used from the buret. This volume is used to calculate the concentration of sodium hydroxide.

Now, if there was excess water in the buret before filling it with the oxalic acid solution, this water would mix with the sodium hydroxide solution as you add it to the flask. As a result, the volume of sodium hydroxide solution used, as indicated by the buret, would include the volume of the excess water.

To calculate the concentration of the sodium hydroxide solution, you need to subtract the volume of the excess water from the total volume indicated on the buret. This will give you the corrected volume of sodium hydroxide solution used.

Once you have the corrected volume, you can use it in the standardization calculations to determine the concentration of the sodium hydroxide solution accurately.

So, in conclusion, the excess water in the buret would increase the volume indicated when you measure the sodium hydroxide solution. To obtain an accurate concentration, you need to correct for the volume of the excess water by subtracting it from the total volume indicated on the buret.