The Question Is:

"A student weighs 0.347 g of KHP on a laboratory balance. The KHP was titrated with NaOH and the concentration of the NaOH determined to be 0.110 M. For the second titration, the student correctly diluted 6 M HCl from the reagent shelf using a graduated cylinder to obtain approximately 0.6 M HCl. This solution was titrated with the original NaOH solution. The student calculated the concentration of NaOH from the experiment to be 0.099 M. In which experiment should the student be more confident of the concentration of the NaOH solution? Why?"

I believe the second titration would be more accurate due to it being titrated with the original amount of NaOH and so im assuming that its concentration would yield a better result. Would that be the case, is there anything im neglecting?

Anyone know if my answer is correct?

Can anyone give me an update on this?

You are correct in identifying that the second titration should provide a more accurate result for the concentration of the NaOH solution. Here's why:

In the first titration, the student weighed KHP on a laboratory balance. The accuracy of the weighing depends on the precision of the balance. However, there can be some inherent errors in the weighing process, such as variations in the balance or human error, that could affect the accuracy of the measured mass of KHP.

In the second titration, the student correctly diluted HCl from a reagent shelf to obtain the desired concentration. Dilution involves accurately measuring a concentrated solution and adding a specific volume of solvent to achieve the desired concentration. This process generally provides a more precise and accurate concentration compared to the weighing of a solid, as it involves fewer inherent sources of error.

Additionally, in the second titration, the student titrated the diluted HCl solution with the original NaOH solution. This means that any inaccuracies in the concentration of the NaOH would have a more direct impact on the results. In the first titration, the NaOH solution was used as the titrant, but the concentration of the NaOH was not directly determined from that experiment.

Therefore, the second titration should provide a more confident estimation of the concentration of the NaOH solution, as it involves a more precise and accurate preparation of the HCl solution and a direct titration with the NaOH solution. However, it's important to note that further analysis is needed to determine the specific sources and magnitudes of errors in both titrations.

You are partially correct in your reasoning. The second titration, where the student used the original NaOH solution to titrate the diluted HCl, is indeed more reliable for determining the concentration of NaOH. However, there are a few more factors that support this conclusion.

Firstly, it is important to note that the concentration of NaOH determined in the first experiment was 0.110 M, while the concentration calculated in the second experiment was 0.099 M. Since the true concentration of NaOH is closer to 0.110 M, the second experiment seems to be more accurate.

Secondly, in the first experiment, the student weighed 0.347 g of KHP on a laboratory balance. Any errors in the weighing process could affect the accuracy of the results. On the other hand, in the second experiment, the student diluted a known concentration of HCl from the reagent shelf. Dilution is a more precise and accurate method than weighing, which reduces the potential sources of error.

Finally, by diluting the concentrated HCl from 6 M to approximately 0.6 M, the student is working with a solution that is closer in concentration to the NaOH solution being titrated. This helps to avoid potential large measurement errors in the titration volume, ultimately leading to more accurate results.

Therefore, considering all these factors, the second titration is generally more reliable for determining the concentration of the NaOH solution compared to the first experiment.