Iodoform test is a common test in chemistry that is conducted for determining the presence or absence of alcohols with the structure R-CH(OH)-CH3 or carbonyl compounds with the structure R-CO-CH3 into an unknown substance. The chemical formula of Iodoform is CHI3 which comes from the organic halogen compound’s family. Iodoform is pale yellow in colour and is volatile in nature. It consists of a distinctive and penetrating odour and a sweetish smell similar to chloroform.
This component is used widely in hospitals as an antiseptic and disinfectant component. Today, in this study material notes on Iodoform, we will talk about the Iodoform test, mechanism of Iodoform test and other related topics in detail. So, let’s get started with Iodoform study material without any further ado.
What is the Iodoform Test?
If sodium hydroxide and Iodine are mixed with a secondary alcohol compound or a methyl ketone in the alpha position, it produces a yellow precipitate of triiodomethane or Iodoform. It is used widely for identifying aldehydes or ketones.
Here is the list of compounds that forms positive Iodoform test –
Secondary Alcohols with Methyl Groups in the Alpha Position
Methyl Ketones
Acetaldehyde
Ethanol
Mechanism of Iodoform Test
Initially, acidic alpha hydrogen is removed by the Hydroxide ion, which ultimately leads to the formation of an enolate ion. Later, this ion moves to displace the iodide ion from an iodine molecule. In order to give R-CO-CI3, this process is repeated two times in a row. At this point, a bond with the carbonyl carbon is formed by the hydroxide ion, which results in the elimination of the CI3– anion and reformation of the carbonyl group. Note a group of R-COOH is formed as well.
Since the basic CI3– ion and carboxylic acid tend to neutralise one another, the precipitation of Iodoform takes place; as a result, yellow iodoform precipitate is formed. Note this test is majorly conducted to determine the pressure or absence of methyl ketones in the unknown compound.
Properties and Preparation of Iodoform
The Iodoform is formed by the inorganic iodides, an aqueous solution that contains acetone and sodium carbonate’s electrolysis. Other names of Iodoform are carbon tri-iodide, tri-iodomethane, and methyl tri-iodide. These names are kept because of the three iodine molecules present in the compound. When applied to wounds, it can cause a kind of burning sensation.
The compound’s molecular weight is 393.73 g/mol; however, its melting point is 121°C. The substance’s purity lies somewhere close to 98 %, which means it is extremely pure. As compared to most substances, it is extremely valuable. When talking about the important features, the common ones are high purity, effectiveness, and balanced composition. Also, this chemical is skin-friendly as it does not lead to any rashes, itching, or irritation. As mentioned earlier, if the wound is opened, it can cause a burning sensation.
Uses of Iodoform
There are several uses of Iodoform. Firstly, it is sometimes used as a disinfectant as well as an antiseptic in hospitals on a small scale. During the 20th century, Iodoform was one of the most important components required in hospitals as it was largely used in medicines to heal wounds rapidly. Also, Iodoform was used to sterilise the hospital instruments as it was believed to be an excellent antiseptic.
However, many side effects were associated with Iodoform. As a result, its usage got suppressed with time and especially after the evolution of better antiseptics. For making dogs and cats powders, Iodoform is one of the significant ingredients along with propanoic acid and zinc oxide as it prevents any infection. Note it’s great for hair removal from ears.
Conclusion
Iodoform is one of the most crucial topics of Chemistry. Iodoform test is a common test in chemistry that is conducted for determining the presence or absence of alcohols with the structure R-CH(OH)-CH3 or carbonyl compounds with the structure R-CO-CH3 into an unknown substance.
In this article, we studied Iodoform in length. We also covered other essential concepts, such as the introduction of Iodoform, Iodoform test, mechanism of Iodoform, properties and preparation of Iodoform in detail. In the end, we also discussed several uses of Iodoform and why people stopped using it. We hope this study material on Iodoform must have helped to attain a greater understanding of the Iodoform along with other related topics.