Molarity Of Naoh Lab Report
Conclusion:
It was apparent that the goal of the lab was to determine the molarity of NaOH through separate trials using bromothymol blue as the indicator. It was expected for the results to conclude that the molarity of NaOH is 0.50M. For trial 1, 0.50M of NaOH was calculated, in trial 2 it was a 0.28M of NaOH and trial 3’s results concluded with 0.54M of NaOH. The results of trial 1 and 3 resemble the most similar and consistent to the expected results of the experiment.
Discussion of Theory:
The lab as able to determine the concentration of NaOH by neutralizing the solution with HCl, a solution which its concentration was already known, this process is called titration. It works by neutralizing a solution from a weak acid/base and its
conjugate ion. During the titration the bromothymol blue acted as the indicator, as the NaOH is added to the flask to indicator would show a color change in the HCl and water. Once the bromothymol blue turns green/pale blue throughout the solution the end point has been reached and the NaOH has been titrated in the HCl solution. The endpoint was determined when there has been a color change in the indicator which is the end to the titration. While the NaOH is added to the HCl the color of the indicator from colorless, to yellow/green, and lastly blue.
Sources of Error:
Sources of error for this lab including over-titration, leftover titrant in the buret from previous trials, and air bubbles in the buret. The over-titration would cause an increase in the molarity because the endpoint is determined visually which isn’t always accurate or reliable. Leftover titrant in the buret from previous trials after each trial could increase the volume read in the buret of NaOH which would cause the reading to be inaccurate. Since the air bubbles weren’t released from the buret before and after each trial, it may cause an increase volume of NaOH solution. The volume found would contain the air bubbles and the solution itself.
It was apparent that the goal of the lab was to determine the molarity of NaOH through separate trials using bromothymol blue as the indicator. It was expected for the results to conclude that the molarity of NaOH is 0.50M. For trial 1, 0.50M of NaOH was calculated, in trial 2 it was a 0.28M of NaOH and trial 3’s results concluded with 0.54M of NaOH. The results of trial 1 and 3 resemble the most similar and consistent to the expected results of the experiment.
Discussion of Theory:
The lab as able to determine the concentration of NaOH by neutralizing the solution with HCl, a solution which its concentration was already known, this process is called titration. It works by neutralizing a solution from a weak acid/base and its
conjugate ion. During the titration the bromothymol blue acted as the indicator, as the NaOH is added to the flask to indicator would show a color change in the HCl and water. Once the bromothymol blue turns green/pale blue throughout the solution the end point has been reached and the NaOH has been titrated in the HCl solution. The endpoint was determined when there has been a color change in the indicator which is the end to the titration. While the NaOH is added to the HCl the color of the indicator from colorless, to yellow/green, and lastly blue.
Sources of Error:
Sources of error for this lab including over-titration, leftover titrant in the buret from previous trials, and air bubbles in the buret. The over-titration would cause an increase in the molarity because the endpoint is determined visually which isn’t always accurate or reliable. Leftover titrant in the buret from previous trials after each trial could increase the volume read in the buret of NaOH which would cause the reading to be inaccurate. Since the air bubbles weren’t released from the buret before and after each trial, it may cause an increase volume of NaOH solution. The volume found would contain the air bubbles and the solution itself.