Kinetics Study on the Reaction between Iodide Ions and Hydrogen Peroxide

 Materials Required

Procedure

Real Lab Procedure

  • Take four 250 ml conical flasks and label them as A, B, C and D.
  • Add 5ml, 10 ml, 15 ml and 20 ml of 0.1 M potassium iodide (KI) solution to the flasks A, B, C and D respectively.
  • Add 10ml of 2.5 M H2SO4 to each flask.
  • To make the volume of the solution 100ml in each flask add water to them.
  • Add 5 ml of starch solution to each flask.
  • Add 10 ml of 0.05 M sodium thiosulphate (Na2S2O3) solution to each flask.
  • Add 5 ml of 3% H2O2 solution to flask A and start the stop- watch immediately.
  • Stir the mixture using a glass rod and wait for the blue colour to appear.
  • Note the time when the blue colour just appears.
  • Repeat the experiment by adding 5 ml of 3% hydrogen peroxide solution to flasks B, C and D and note the time required in each case for the blue colour first appears.

Simulator Procedure (as performed through the Online Labs)

  • You can select the volume of potassium iodide (KI) solution using the slider.
  • Drag the conical flask containing 0.1 M potassium iodide (KI) solution to the measuring jar to measure the solution.
  • Drag the measuring jar to the conical flask to pour the solution in it.
  • Drag the bottle to the measuring jar to measure 10ml 2.5 M sulphuric acid.
  • Drag the measuring jar to the conical flask to pour sulphuric acid in it.
  • Drag the beaker to the measuring jar to measure distilled water.
  • Drag the measuring jar to the conical flask to pour water in it.
  • Drag the bottle to the measuring jar to measure 5 ml starch solution.
  • Drag the measuring jar to the conical flask to pour the starch solution in it.
  • Drag the bottle to the measuring jar to measure 10 ml 0.05 M sodium thiosulphate (Na2S2O3) solution.
  • Drag the measuring jar to the conical flask to pour sodium sulphite solution in it.
  • Drag the bottle to the measuring jar to measure 5ml 3% hydrogen peroxide (H2O2) solution.
  • Drag the measuring jar to the conical flask to pour hydrogen peroxide solution in it.
  • You can get the time taken for the appearance of blue colour from the stopwatch.
  • You can use the embedded worksheet to enter the values.
  • You can plot a graph using the worksheet.
  • To redo the experiment, click the ‘Reset’ button.

Note: Click on the ‘HELP’ button to see the instructions.

Observation

Record the observations as shown in the table given below:

Flask 0.1 M KI solution (ml) 2.5 M H2SO4 (ml) Water (ml) Starch solution (ml) 0.05 M sodium thiosulphate solution (ml) 3% H2O2 (ml) Time (t) for the appearance of blue colour (s)
A 5 10 85 5 10 5  
B 10 10 80 5 10 5  
C 15 10 75 5 10 5  
D 20 10 70 5 10 5  

Conclusion

The rate of the reaction increases with an increase in the concentration of iodide ions.

Precaution

  • Always use freshly prepared solution of sodium thiosulphate.
  • Concentration of KI solution should be higher than the concentration of sodium thiosulphate solution.
  • Use freshly prepared starch solution. 

Cite in Scientific Research:

Nedungadi P., Raman R. & McGregor M. (2013, October). Enhanced STEM learning with Online Labs: Empirical study comparing physical labs, tablets and desktops. In Frontiers in Education Conference, 2013 IEEE (pp. 1585-1590). IEEE.

Cite this Simulator: