Question

Explain the role of the starch iodide test during the oxidation reaction and explain the reaction that was used to identify the formation of the product in that reaction.

*The experiment was Cyclohexanone from Cyclohexanol: Cyclohexanol + NaCl-----Acetic Acid---> Cyclohexanone + NaCl + H2O

Answer 1

Answer 2

The starch iodide test is a common chemical test used to detect the presence of free iodine in a solution. In the context of the given reaction involving the conversion of cyclohexanol to cyclohexanone, the starch iodide test is used to identify the formation of iodine, which is an intermediate product in the reaction.

The oxidation of cyclohexanol to cyclohexanone involves the use of a strong oxidizing agent, such as sodium hypochlorite (NaCl) in the presence of acetic acid (CH3COOH). The reaction can be represented as follows:

Cyclohexanol + NaCl (sodium hypochlorite) → Acetic Acid → Cyclohexanone + NaCl + H2O

During the oxidation process, cyclohexanol is converted to cyclohexanone, and a key intermediate in this reaction is the formation of iodine (I2) from the reaction of sodium hypochlorite and acetic acid. The presence of free iodine is a characteristic feature of the reaction, and this is where the starch iodide test comes into play.

The starch iodide test is based on the fact that iodine molecules can form a blue-black complex with starch molecules. In the absence of free iodine, the starch iodide test solution remains colorless. However, if free iodine is present, it reacts with the starch in the test solution to produce the blue-black complex, indicating the formation of iodine.

The test is performed by adding a few drops of the starch iodide test solution to the reaction mixture after the oxidation reaction has taken place. If the reaction has been successful and free iodine has been formed, the test solution will turn blue-black, confirming the presence of iodine, which is an intermediate product in the oxidation of cyclohexanol to cyclohexanone.

Overall, the starch iodide test is a useful tool in organic chemistry for detecting the presence of iodine and confirming the progress of oxidation reactions like the one described in the experiment.