Performing Titrations [RPA 1]

Question 1

What is the equivalence point?

Answer 1

• When the 2 solutions have reacted completely
• Indicated by a change in colour of an indicator

Question 2

Steps of a Titration :

Answer 2

1. Add known volume of solution into a conical flask using a volumetric pipette
2. Put other solution in burette
3. Add a few drops of indicator to the solution in the conical flask
4. Slowly open the tap on the burette and a little bit at a time, carefully add drops of one solution to the other until the indicator starts to permanently change colour
5. As equivalence point is neared, add solution dropwise slowly
6. Close tap once all solution has been added
7. Multiple repeats until concordant results are obtained

Question 3

What is the uncertainty of a burette?

Answer 3

+ or - 0.05cm ^3

Question 4

What are concordant results?

Answer 4

• Results within 0.1cm ^3 of each other

Question 5

How to calculate uncertainty?

Answer 5

• Usually + or - 10 cm ^3
• Uncertainty doubled from 0.05 (half the smallest marking) because 2 burette readings (initial and final) are made to obtain the titre

Question 6

How to calculate PERCENTAGE uncertainties?

Answer 6