Chemical Kinetics

Ronnie Bermundo

Experiment #3 Chemical Kinetics

Methodology

Part I: Effect of Concentration on the Rate of Reaction

First, an “X” mark was put on the bottom of the 50-mL beaker. Required number of volumes of Na2S2O3 and water in the beaker. Runs 1 to 3 was performed (refer to the table below).

Determination of the Effect of Concentration on the Rate of Reaction |

Run | Volume of 0.15 M Na2S2O3 (mL) | Volume of water (mL) | Volume of 3M HCl (mL) |

1 | 10.0 | 3.0 | 2.0 |

2 | 5.0 | 8.0 | 2.0 |

3 | 2.5 | 10.5 | 2.0 |

4 | 5.0 | 1.0 | 1.5 |

5 | 5.0 | 1.5 | 1.0 |

6 | 5.0 | 2.0 | 0.5 |

Then required volume of 3M HCl was then added to the beaker. The time was recorded when the “X” mark no longer visible. This was also done from Runs 1 to 3. For runs 4 to 6, 3.0M HCl was first added to water in the beaker then 0.15M Na2S2O3 further. The time of reaction was recorded.

Part II: Effect of Temperature on the Rate of Reaction

Run 3 (Part I) was performed at three different temperatures: one in an ice bath, one at ambient and another at elevated temperature. The required amount of 0.15M Na2S2O3 and water was then put to the 50-mL beaker with the “X” mark then the required amount of 3.0M HCl to a test tube. Then the 50-mL beaker and the test tube in a 500-mL beaker filled with water was place at the desired temperature. Then the temperature of the solution when constant value reached was recorded. Finally the hydrochloric acid was added to the thiosulfate solution while the beaker was in the water bath. The reaction times to make the “X” mark not visible were recorded.

Part III: Catalysis

A. Oxidation of Tartrate by Hydrogen Peroxide

A hot water bath maintained at 65°C was prepared. Then Test Tube 1 and Test Tube 2 were prepared. 5mL of 0.3M sodium tartrate and 2mL 6% H2O2 but 8 drops of 0.3M CoCl2 was added to Test Tube 2. Both test tubes were then put in the hot water bath.

B. Reaction of Oxalate with Permanganate

Solution of 1 mL...