This chemical reaction involves neutralization, where an acid and base react to produce a neutral solution of salt and water. As this information is provided, the known concentration of NaOH(aq) is 0.25M. It is necessary to rinse out the burette with sodium hydroxide solution before starting titration, as the concentration of the base can be affected by the water used to clean the burette. At the same time, when cleaning the burette it may not have been washed thoroughly . By rinsing with sodium hydroxide solution, it ensures that the burette is clean and will not affect the results of the experiment. Running a particular titration at least three times is good practice, as it allows for the reproducibility of the lab to be tested. If the
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Even though volume is increasing, the moles and volume of HCl(aq) in the erlenmeyer flask is still constant. The objective is to find the concentration of the unknown acid, and since the moles and volume do not change, therefore the results of the concentration will not either. Vinegar is an acidic solution; by rinsing with vinegar after using shampoo, a neutralization reaction occurs, as an acid plus a base produce salt and water. People may not want their hair to be basic, therefore they decide to use vinegar to neutralize the shampoo. A possibility that could have affected the results of the lab is the endpoint determination. Referring back to the results table, it can be seen that the third and fourth test both resulted in a light pink colour. Despite the similarity in the colour, the volume of NaOH(aq) used is different. This is due to the fact that indicator does not change colour immediately. With acid-base titration, the colour disappears as the mixture is swirled in the erlenmeyer flask. The first colour change can occur too late in the process of titration. This behavior of indicators can affect the final volume of NaOH(aq) used, which can lead to the calculation of unknown concentration being wrong. The concentration of the indicator used in the experiment can also change the final results. Even if two drops were added, the indicator is also an acid and the concentration can cause more base to be
Even though volume is increasing, the moles and volume of HCl(aq) in the erlenmeyer flask is still constant. The objective is to find the concentration of the unknown acid, and since the moles and volume do not change, therefore the results of the concentration will not either. Vinegar is an acidic solution; by rinsing with vinegar after using shampoo, a neutralization reaction occurs, as an acid plus a base produce salt and water. People may not want their hair to be basic, therefore they decide to use vinegar to neutralize the shampoo. A possibility that could have affected the results of the lab is the endpoint determination. Referring back to the results table, it can be seen that the third and fourth test both resulted in a light pink colour. Despite the similarity in the colour, the volume of NaOH(aq) used is different. This is due to the fact that indicator does not change colour immediately. With acid-base titration, the colour disappears as the mixture is swirled in the erlenmeyer flask. The first colour change can occur too late in the process of titration. This behavior of indicators can affect the final volume of NaOH(aq) used, which can lead to the calculation of unknown concentration being wrong. The concentration of the indicator used in the experiment can also change the final results. Even if two drops were added, the indicator is also an acid and the concentration can cause more base to be