Chemical kinetics are governed by the mathematics of systems of differential equations (Thermodynamics and Kinetics). This means that the rate of any chemical reaction is determined by the type, and amount, of reactants present. Note the rate of a reaction is how fast it occurs. Furthermore, such rate equations can either be distinctively linear or non-linear when graphed. Non-linear equations are supposedly more complex as they generally react to small changes within its parameters (Thermodynamics and Kinetics). This could include minimal errors and environmental changes. Scientists refer to such equations as chaotic and rather unpredictable (Thermodynamics and Kinetics).
An iodine clock reaction is a common example of a complex non-linear …show more content…
1992), it became evident that such reactions (mentioned above) took place over the course of three smaller reactions. The equations below are examples from a Hydrogen Peroxide Iodine Clock Reaction:
Reaction 1: 〖3I〗_((aq))+H_2 O_2+〖2H〗_((aq))→I_(3(aq))+〖2H〗_2 O_((l))
Reaction 2: I_(3(aq))+〖4S〗_2 O_(3(aq))→〖3I〗_((aq))+〖2S〗_4 O_(6(aq))
Reaction 3: 〖2I〗_(3(aq))+starch →starch I_5 complex +I_((aq)) (Shakhashiri, B. 1992).
The first equation/reaction (determining step) shows that the iodide particles react with hydrogen peroxide to form triiodide ions. However, these ions just as quickly return back to iodide particles once combined with the second reaction or, more specifically, the sodium thiosulfate. This is due to equilibrium, which maintains a balanced state (by shifting to either the right or the left) despite the formation and consumption of several particles involved, simply meaning these equations are reversible - this is Le Chatelier’s Principle. After the sodium thiosulfate has been entirely consumed by the once triiodide ions, the iodide ions now react with the starch to form a dark blue/purple/black colour (Shakhashiri, B. …show more content…
These factors included temperature, concentration, and the addition of a catalyst. The results obtained positively relate back to the aim stated, as they demonstrate significant differences between each temperature, and concentration (for example). Despite such differences, it was concluded that in response to the increase of each chosen stimulus (temperature, concentration and catalyst), the reaction rate of the hydrogen peroxide iodine clock too increased (essentially this is the Collision Theory). This proves our hypothesis also. In the tables above, it is evident that when the concentration of sodium thiosulfate was increased, the results showed to be abnormal and unexpected. This abnormality is assumed due to the decrease in the solution’s reaction time, despite the increase of concentration within the chemical. Initially it was thought that this variation occurred due to dependant variables (or environmental changes), however after further research this was found to be untrue. Instead this variation occurred as sodium thiosulfate is a limiting reagent. However, the graphs above do show a general movement that is increasing in both the stimuli and the reaction
An iodine clock reaction is a common example of a complex non-linear …show more content…
1992), it became evident that such reactions (mentioned above) took place over the course of three smaller reactions. The equations below are examples from a Hydrogen Peroxide Iodine Clock Reaction:
Reaction 1: 〖3I〗_((aq))+H_2 O_2+〖2H〗_((aq))→I_(3(aq))+〖2H〗_2 O_((l))
Reaction 2: I_(3(aq))+〖4S〗_2 O_(3(aq))→〖3I〗_((aq))+〖2S〗_4 O_(6(aq))
Reaction 3: 〖2I〗_(3(aq))+starch →starch I_5 complex +I_((aq)) (Shakhashiri, B. 1992).
The first equation/reaction (determining step) shows that the iodide particles react with hydrogen peroxide to form triiodide ions. However, these ions just as quickly return back to iodide particles once combined with the second reaction or, more specifically, the sodium thiosulfate. This is due to equilibrium, which maintains a balanced state (by shifting to either the right or the left) despite the formation and consumption of several particles involved, simply meaning these equations are reversible - this is Le Chatelier’s Principle. After the sodium thiosulfate has been entirely consumed by the once triiodide ions, the iodide ions now react with the starch to form a dark blue/purple/black colour (Shakhashiri, B. …show more content…
These factors included temperature, concentration, and the addition of a catalyst. The results obtained positively relate back to the aim stated, as they demonstrate significant differences between each temperature, and concentration (for example). Despite such differences, it was concluded that in response to the increase of each chosen stimulus (temperature, concentration and catalyst), the reaction rate of the hydrogen peroxide iodine clock too increased (essentially this is the Collision Theory). This proves our hypothesis also. In the tables above, it is evident that when the concentration of sodium thiosulfate was increased, the results showed to be abnormal and unexpected. This abnormality is assumed due to the decrease in the solution’s reaction time, despite the increase of concentration within the chemical. Initially it was thought that this variation occurred due to dependant variables (or environmental changes), however after further research this was found to be untrue. Instead this variation occurred as sodium thiosulfate is a limiting reagent. However, the graphs above do show a general movement that is increasing in both the stimuli and the reaction