Risk assessment for harcourt essen
Aims To investigate the effect of varying the concentration of H2O2 has on the reaction, and to determine the respective order of reaction. To investigate the effect of varying the concentration of KI has on the reaction, and to determine the respective order of reaction. To investigate the effect of varying the temperature has on the reaction, and to determine the respective order of reaction. To investigate the effect of introducing Ammonium Molybdate to the reaction Arrhenius stuff
The reaction of Hydrogen Peroxide and Iodide ions in an acidic medium: 3 I-(aq) + H2O2(aq) + 2 H+(aq) I3-(aq) + 2 H2O(l)
Step 1. H2O2(aq) + I-(aq) IO-(aq) + H2O(l)
Step 2. IO-(aq) + H+(aq) HOI(aq)
Step 3. HOI(aq) + 2 I-(aq) + H+(aq) I3-(aq) + H2O(l)
In this reaction the three iodide ions are oxidised to form the triiodide ion. This occurs in three steps. Firstly, the peroxide molecule oxidises a single iodide ion, to form a hypoiodite ion, and a molecule of water. This is the slowest step in the reaction, meaning that any change in reaction conditions that speeds up this reaction should speed up the reaction as a whole. This reaction step is not reversible. The hypoiodite ion exists in a dynamic equilibrium with hypoiodous acid, HOI. This is then converted by two separate reactions. The first is significantly faster, and it is this reaction that forms the final product of the reaction as a whole the triiodide ion. The hypoiodous acid reacts with two iodide ions and a proton to form a water molecule, and the triiodide ion. Hypoiodous acid can also decay of its own accord to form iodic acid (HIO3), I2 and water, although this reaction is significantly slower, and should not make a significant impact upon my results.
The triiodide/starch complex
Starch consists of a mixture of two molecules, amylopectin and amylose, which are generally present in approximately 80:20 proportions by mass. Amylopectin is a giant molecule, composed of varying numbers
The reaction of Hydrogen Peroxide and Iodide ions in an acidic medium: 3 I-(aq) + H2O2(aq) + 2 H+(aq) I3-(aq) + 2 H2O(l)
Step 1. H2O2(aq) + I-(aq) IO-(aq) + H2O(l)
Step 2. IO-(aq) + H+(aq) HOI(aq)
Step 3. HOI(aq) + 2 I-(aq) + H+(aq) I3-(aq) + H2O(l)
In this reaction the three iodide ions are oxidised to form the triiodide ion. This occurs in three steps. Firstly, the peroxide molecule oxidises a single iodide ion, to form a hypoiodite ion, and a molecule of water. This is the slowest step in the reaction, meaning that any change in reaction conditions that speeds up this reaction should speed up the reaction as a whole. This reaction step is not reversible. The hypoiodite ion exists in a dynamic equilibrium with hypoiodous acid, HOI. This is then converted by two separate reactions. The first is significantly faster, and it is this reaction that forms the final product of the reaction as a whole the triiodide ion. The hypoiodous acid reacts with two iodide ions and a proton to form a water molecule, and the triiodide ion. Hypoiodous acid can also decay of its own accord to form iodic acid (HIO3), I2 and water, although this reaction is significantly slower, and should not make a significant impact upon my results.
The triiodide/starch complex
Starch consists of a mixture of two molecules, amylopectin and amylose, which are generally present in approximately 80:20 proportions by mass. Amylopectin is a giant molecule, composed of varying numbers