Like any titration, neutralization titrations depend on a chemical reaction between the unknown solution and a standard reagent. The point of chemical equivalence is indicated by a chemical indicator or an instrumental measurement. When the color changes to the specified color, the titration has reached endpoint. The mole ratio and volume relates the concentration of the solutions. The more the number of moles of the base is used the more number of moles are needed to neutralize. To increase the number of moles you can increase the concentration or decrease the volume. If we take an overview of the reaction, the protons from the HCl moved to the NaOH or the HCl donated H+ ions to the solution and NaOH gave OH- ions to the solution. And as a result a salt (NaCl) and water were formed.
The methods used were quiet precise. The burette and pipette have some limitations due to being less precise. The volume of burette limited the amount of trial that were attempted and it needed to be refilled. The Erlenmeyer flask resisted the splashing of the solution outside the flask which would have been occurred due to swirling. This caused the value, of the number of moles of HCl needed to neutralize NaOH, to be more accurate.
Experimental errors could possibly be as follow:•NAOH was lost to splashing before the end point was reached•Burette may have been contaminated with some other solution other than the one being tested•Reading of the burette may have been off•Some sir bubbles would have been there in the nozzle of the burette•Contamination of samples may interfere with the titration’s results•The amount of the acid added to the base would be more than requiredA few steps can be taken to avoid the experimental errors such as:
•Reading of burette should be to 2 decimal places approximation for higher accuracy•Take readings at eye level to avoid parallax errors•Take care when adding, mixing, or cleaning•Use 0.10 mL increments instead of 0.50 mL•Use burette with a narrower tube can be usedExtension6. The pink color of phenolphthalein appears when the solution is neutral. And as we addHCl to NaOH we are neutralizing the solution. As we reach the endpoint the solution is nearly neutral and that’s why the pinkish color disappears slowly near the endpoint.
7.It is a good idea to carry out titrations in triplicate because we get a more precise value. The answer is closer to the exact value. It also increases the accuracy of the answer.
8.Because at some points only a small or a half drop is enough to reach the endpoint, so u might be told to wash off a drop of solution into the Erlenmeyer flask using distilled water.
9. Addition of several millilitres of distilled water to the Erlenmeyer flask during titration would affect the results of titrations. By adding distilled water we would dilute the base in the Erlenmeyer and less volume of the acid would be required to neutralize the base.