F.6 Chemistry/TAS 8/P.()
Date: 01/12/2010
Objective
To determine the proportions of sodium carbonate and sodium hydroxide in a mixture solution using double indicator method.
Procedures
- 25 cm3 of the mixture solution was pipetted into a conical flask.
- Two drops of phenolphthalein indicator were added into the conical flask.
- The mixture solution was titrated with the given standard hydrochloric acid(0.098M).
- The mixture was titrated to the end-point.
- At the end point, the pink colour of phenolphthalein indicator was just discharged.
- The burette reading (x) was recorded.
- Two drops of methyl orange and a further quantity of acid were added
- The mixture was titrated to the end-point.
- At the end point ,the yellow colour of the methyl orange changed to orange.
- The reading of that further quantity of acid (y) was recorded.
- The steps above were repeated 3 times.
This is a preview of the whole essay
Peer Reviews
Here's what a star student thought of this essay
Quality of writing
Spelling, punctuation and grammar is very good. Technical terms are used appropriately. Overall a good piece of work.
Level of analysis
The analysis in the questions is generally good but explaining what is being calculated would have been helpful. If the student had made a hypothesis initially, it would have been possible to compare this with the final result and make a better conclusion, looking at the reliability and accuracy of the results. The references are good but should be shown where they have used through the text.
Response to question
Initially, the candidate should expand on the objectives to include their predictions. It is also recommended to put some of the known theory before the method to help agree with your predictions. The method and results sections are excellent. A diagram could have aided the method but wasn't essential.
