BRIGGS RAUSCHER OSCILLATING CLOCK COURSEWORK
BRIGGS RAUSCHER OSCILLATING CLOCK COURSEWORK
Aim:
To investigate the effect of temperature on the rate of reaction.
To investigate the order of reaction with respect to hydrogen peroxide and ethanoic acid (acetic acid) by the use of an oscillating clock reaction.
To determine the activation enthalpy with and without catalytic ions and use this to compare the effectiveness.
To investigate the rate equation, rate constant and possible mechanism for this reaction.
Background research:
The Briggs-Rauscher reaction
The Briggs-Rauscher reaction also known as the oscillating clock is a demonstration of a chemical oscillator reaction. It happens when three prepared colourless solutions are mixed together and this will slowly turn into an amber colour to deep blue clear for approximately 3-5 minutes as it repeats itself. The reaction ends up as a blue-black mixture. [1]
Chemistry of the reaction
The mechanisms of the Briggs Rauscher oscillating clock reaction have many features. Firstly, when the oscillation occurs, the mixture is not at equilibrium and an energy releasing reaction occurs whose energy moves the oscillating sideshow. The energy-releasing reaction can follow two different ways, and it periodically shifts from one way to another. One way produces an intermediate and the other one consumes it, and the concentration of this intermediate functions act as a trigger for the shifting from one way to the other. When the concentration of the intermediate is low, the reaction follows the producing way which leads to a high concentration of intermediate. When the concentration of the intermediate is high, it shifts to the consuming way and the concentration of the intermediate decreases. This reaction return to the producing way and it repeatedly shifts from one way to another. [2]
In Briggs Rauscher reaction, oscillation happens due to the evolution of oxygen and carbon dioxide gas and the concentrations of iodine and iodide ions. The overall reaction of Briggs
Aim:
To investigate the effect of temperature on the rate of reaction.
To investigate the order of reaction with respect to hydrogen peroxide and ethanoic acid (acetic acid) by the use of an oscillating clock reaction.
To determine the activation enthalpy with and without catalytic ions and use this to compare the effectiveness.
To investigate the rate equation, rate constant and possible mechanism for this reaction.
Background research:
The Briggs-Rauscher reaction
The Briggs-Rauscher reaction also known as the oscillating clock is a demonstration of a chemical oscillator reaction. It happens when three prepared colourless solutions are mixed together and this will slowly turn into an amber colour to deep blue clear for approximately 3-5 minutes as it repeats itself. The reaction ends up as a blue-black mixture. [1]
Chemistry of the reaction
The mechanisms of the Briggs Rauscher oscillating clock reaction have many features. Firstly, when the oscillation occurs, the mixture is not at equilibrium and an energy releasing reaction occurs whose energy moves the oscillating sideshow. The energy-releasing reaction can follow two different ways, and it periodically shifts from one way to another. One way produces an intermediate and the other one consumes it, and the concentration of this intermediate functions act as a trigger for the shifting from one way to the other. When the concentration of the intermediate is low, the reaction follows the producing way which leads to a high concentration of intermediate. When the concentration of the intermediate is high, it shifts to the consuming way and the concentration of the intermediate decreases. This reaction return to the producing way and it repeatedly shifts from one way to another. [2]
In Briggs Rauscher reaction, oscillation happens due to the evolution of oxygen and carbon dioxide gas and the concentrations of iodine and iodide ions. The overall reaction of Briggs