User:Big B1326

Evaluation

Limitations:

•	Rinsing out of the conical flask must be thorough to prevent alteration of the concentration of the solution for the next titration, but also excess water must be removed after rinsing. •	Burette readings must be taken to 2 decimal places. •	The observed end point for the reaction may differ on the observer. •	Placing the Burette vertically and level. •	Air bubbles forming in the Volumetric Pipette.

The key points of the experiment that are important are the filling of the volumetric pipette, recording the final burette reading, period before the Solution in the Burette is stopped and added slowly. When doing the experiment: •	 I gradually added the Na2CO3 (aq) solution until the bottom of the meniscus reaches the 250ml mark. •	The final burette reading is made from the bottom of the meniscus. •	Paid close attention to the appearance of colour change in the solution so I could stop running it into the conical flask and add it gradually. •	When adding gradually small volumes are added then shaken in the flask and if there is a colour change that lasts longer than 20 seconds it is considered the end point.

Uncertainty:

•	The uncertainty