Catalysis by Cobalt(II) Ion

MATERIALS

-          300mL 8.3% (W/V) potassium sodium tartrate

-          100mL 6% (V/V) hydrogen peroxide

-          25mL 4% (W/V) cobalt(II) chloride hexahydrate

-          1 large demonstration test tube

-          Hot plate

-          600mL beaker

PRESENTATION (preform procedure 2 first to use as a control)

1.      (the catalyzed reaction)

1.      Heat 300mL of 8.3% potassium sodium tartrate to a boil and pour it into the large test tube

2.      Pour 100mL of 6% hydrogen peroxide into the large test tube

3.      Add 24mL of 4% cobalt(II) chloride to the large test tube.  The initial color of the solution in the test tube after this addition will be pink.

4.      Within a few seconds, a reaction will start changing the color to a dark green

5.      After about one minute, the color of the solution will revert back to pink

2.      (the non-catalyzed reaction)

-          Repeat steps 1 & 2 from procedure 1

HAZARDS (MSDS Links)

Sodium potassium tartrate:  http://www.sciencelab.com/msds.php?msdsId=9924692

Hydrogen Peroxide:  http://sargentwelch.com/pdf/msds/Hydrogen_Peroxide_6Pct_347.00.pdf

Cobalt II chloride:  http://www.sciencelab.com/msds.php?msdsId=9925768

REFERENCES

P.T. Ruda, J. Chem. Educ., 55,652 (1978)