Data Analysis
| Parameter | Trial 1 | Trial 2 | Trial 3 |
| Concentration of NaOH solution (M) | 0.09934 | 0.09934 | 0.09934 |
| Volume of NaOH solution to reach the equivalence point (mL) | 14.178 | 13.880 | 13.861 |
| Amount of NaOH to reach equivalence point (mol) | 0.001408 | 0.001379 | 0.001377 |
| Amount of HCl in the solution (mol) | 0.001408 | 0.001379 | 0.001377 |
| Concentration of HCl solution (M) | 0.07040 | 0.06895 | 0.06885 |
| Average concentration of the HCl solution (M) | 0.06940 | 0.06940 | 0.06940 |
Calculations
- Number of moles of NaOH needed to reach the equivalence point.
Trial 1
Trial 2
Trial 3
The number of moles of HCl is the same as the number of moles of NaOH because the stoichiometric ratio is 1:1.
2. Concentration of HCl
Trial 1
Trial 2
Trial 3
3. Average Concentration of HCl
Conclusion
The purpose of this lab is to determine the molar concentration of a strong acid solution by titrating measured volumes with a strong base of known concentration. This was done by using titration which is used to determine the quantity of one reactant when the quantity of the other reactant is known. Once the solutions react in stoichiometric ratios the equivalence point is reached. A titrant, a reagent of known concentration, is used to react with a measured volume of the reactant. The known reactant is NaOH. In the previous lab the concentration of NaOH was determined to be 0.9934 M. When a basic solution, such as NaOH, is added to an acidic one, such as HCl, hydroxide ions from the base react with the hydronium ions fromthe acidic solution. This creates water. The pH measures the molarity of the hydronium ions. When the number of moles of hydroxide ions added is equal to the moles of hydronium ions, the pH jumps sharply. This is when the equivalence point is reached which is this volume of NaOH that is needed to reaction with HCl in a stoichiometric ratio.
After doing all of the calculations for this lab, the concentration of HCl was found to be 0.0694 M. This is not accurate results because the concentration should have been at or close to 0.1 M HCL. Some errors that could have occurred were making the solution of HCl incorrectly, making some errors finding the concentration of NaOH in the last lab or not accurately calibrating the pH sensor. This experiment could have been made better in the future by taking more time to make sure all of the solutions are accurately made and properly standardized. Making sure all of the equipment on the automatic titrater is calibrated and working properly.