4H+(aq) + 4I−(aq) + O2(g)→ 2I2(aq) + 2H2O(l)
"An accumulation of iodine in a box of table salt would result in the salt's becoming yellow to red in color and the development of a very noticeable bad taste. To avoid this problem, a reducing agent, typically dextrose (C6H12O6) is added to reduce back to colorless iodide any iodine that may be formed" (Wright, 2007). The chemical equation below shows the reduction of iodine to iodide by dextrose:
C6H12O6(aq) + I2(aq) + H2O(l)→ C6H12O7(aq) + 2HI(aq)
In this project, you will test various samples of salt to determine whether they contain this essential micronutrient. In the test, hydrogen peroxide (H2O2) reacts with iodide ion present in the salt sample:
2H+(aq) + 2I−(aq) +H2O2(aq)→ I2(aq) + 2H2O(l)
Starch is also added to the testing mixture, so that any iodine produced will form a blue starch-iodine complex. You will use the colored starch-iodine complex as an indicator, identifying the presence (or absence) of iodine in...