Effect of Concentration of Sodium Thiosulphate on its Rate of Reaction with Sulphuric Acid

5C students carried out their investigation to study the effect of concentration of sodium thiosulphate on its rate of reaction with sulphuric acid on 24 Jan 2011.

Before the experiment, they were ready with their experiment plan. Most of them were able to write a satisfactory experiment plan. However, the aim of the experiment, problem statement were not specific.  Some even were not ready with their table. Hopefully they would improve after discussing with me.

The students were able to carry out the experiment with correct technique & skills. Well done, 5C students!

The student was taking time for mark 'X' dissapear from view.

 

Cooperation is shown througout the experiment.



The conical flask is swirled once sulphuric acid is added into sodium thiosulphate.

Mark 'X' is observed from top of the conical flask. The other pair of students were discussing their data.

How to get prepared for Paper 3 Chemistry SPM?

Many of my students keep on asking me about how to score Paper 3.  They are not sure whether they are ready for it or they are applying the correct learning strategies...

I think the most important is to get to know the format of Paper 3 first.

Different scientific skills are evaluated in this paper:

1. observing
2. classifying
3. measuring and using numbers
4. inferring
5. predicting
6. communicating
7. using space-time relationship
8. interpering data
9. defining operationally
10. controlling variables
11. hypothesizing
12. planning an experiment(problem stat/ement/aim of experiment, hypothesis/variables, materials & apparatus, procedure and tabulation of data)

   The scientifil skils are acquired by the students slowly when they plan, carry out experiments and make a report in their class.  PEKA is another way of assessment to evaluate students' scientific skills and attitudes too.
 
  So, the best strategy I would suggest is to go through the above list and identify which one you are still weak in.  Go through the past year questions or trial question from different state and try to study why an answer for a particular skill is considered as excellent answer(Score 3).

All the best! All the SPM 2009 Candidates.

To determine the end point in the titration of hydrochloric acid and sodium hydroxide solution using acid-base indicator

PEKA 2

Titration is an important method to determine the concentration of a solution.
Through Acid-base titration, concentration of acidic or alkaline solution can be determined.

Format of the Report
(Refer practical book page 103)

1. Aim
2. Materials
3. Apparatus
4. Diagram
5. Procedure
6. Result
7. Observation
8. Discussion
9. Conclusion

Please get ready before come to the lab. You might find video in this blog that show the correct method to carry out acid-base titration. 

Schedule for PEKA is as follows :
4E : 15/9/09(Tuesday)

4D : 18/9/09(Friday)*
*Subjected to changes, might be earlier.