To study kinetic of lodination of propanone by colorimeter & to determine the rate equation of the rxn b/w acidified propanone sol and lodine

Aim :- 

To study kinetic of lodination of propanone by colorimeter & to determine the rate equation of the reaction between acidified propanone sol and lodine.

Requirements :- 

• Colorimetry setup
• Micropipette
• 5ml graduated pipette
• IMMER I propanone solution
• Deionised water.

Theory :- 

The concentration of iodine decreases and the brown colour intensity of the reacting solution also decreases. The change in colour intensity allows the use of colorimetry to follow reaction kinetics. Colorimetry works on the principle of beer lambert Law, which states that the art of light transmitter through a coloured solution decreases exponentially with increase in conc (c) of coloured solution and increase in path length (L) of cuvette.

This is valid for only dilute solutions.Decrease in conc. of species can be measured by the change in absorbance. Relative rate of disappearance of iodine, is measured from the absorbance us time plot. This avoid making of calliberation curve of run wirt. each reactant ů determined by separately the conc. of each of reactants. A fire order sinn wirt. CH₂COCH,, μ confirmed, while keeping the conc. of Igrap) & H² cap. is constant, the initial state of dec of cone of Ig (ag) doubly as the cone of CHCOCH, cap).

Procedure :- 

Calibration of the colorimeter. Setup the interface box and connect it to the computer. Calliberate the colorimeter as described in the manual. We appropriate filter (Blue here).

1. Start the program for colorimetes with graphical display. Choose the option for transmittance and time interval for 10 mini 2) wring a clean pipette, tranger 0-25 core of IM CH₂ COCHS $0.75 cm³ of IM HSO into a clear cuvette.
2. Add deionized water (1.50 cm³)
3. Mine them by capping the cervette & shaking 
4. Uncap the cuvette, wing a micro tip plastic pipette, quickly add 30 drops of 0.02M lodine solution. Cap the cuvette, cover it into the -cell compartment of colorimeter.
5. Nove readings until the transmitted signal flattens
6. Convert Y-anu to absorbance scale & measure the "initial rate of dec in absorbance ace to software manual. Save data file.
7. Repeat steps 3 to 7 for other turns & record data for lame.

Precaution :- 

1. Low cone of analyte solution is used because high conc may cause disturbance in charge. distribution and refractive index.
2. Always rince the cuvette with the solutions clean the surface to avoid the disturbance in path length.

Result :- 

Reaction has overall second order.