Acid-Base Titration

Question 1

Titration procedure

Answer 1

1. Add a measured volume of one solution to a conical flask using a pipette.
2. Add the other solution to a burette, and record the initial burette reading to the nearest 0.05cm^3
3. Add a few drops of an indicator to the solution in the conical flask
4. Run the solution in the burette into the solution in the conical flask, swirling the conical flask throughout to mix the two solutions evenly. Eventually, the indicator will change colour at the endpoint of the titration. The endpoint is used to indicate the volume of one solution that reacts with the volume of the second solution.
5. Record the final burette reading. The volume of solution added from the burette is called the titre, which is calculated by subtracting the initial from the final burette reading.
6. A rough titration is carried out first, to find out the approximate titre.
7. The titration is then repeated accurately, adding the solution dropwise when close to the perceived endpoint. Further titrations are carried out until two titres are concordant, within 0.10 cm^3

Question 2

Preparing standard solutions

Answer 2

1. The solid is first weighed accurately
2. The solid is dissolved in a beaker using a reasonable amount of distilled water so that it will be greater than the graduation line on the volumetric flask.
3. This solution is transferred to a volumetric flask. The last traces of the solution are rinsed into the flask with distilled water
4. The flask is carefully filled to the graduation line by adding distilled water dropwise until the bottom of the meniscus lines up exactly with the graduation line.
5. Finally, the volumetric flask is slowly inverted several times to mix the solution thoroughly