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Last updated date: 29th May 2024
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What is Formalin?

Formalin is another name for formaldehyde. Following a previous trade name, "formalin," "formaldehyde" was first used as a generic trademark in 1893. The simplest aldehyde is formaldehyde, which has the formula CH2O and is made up of hydrogen, carbon, and oxygen. At room temperature, formaldehyde is one of a wide group of chemicals known as volatile organic compounds, which evaporate and become gaseous.

Formalin Composition

Formalin is a water-based saturated solution of formaldehyde gas. It contains about 40% formaldehyde gas (by volume) or 37% formaldehyde gas (by weight), as well as a small amount of stabilizer. The general stabilizer, in this case, is 10-12 percent methanol, which helps to avoid formaldehyde polymerization. Formaldehyde solution is very unstable without a stabilizer, and it appears to polymerize, forming insoluble macromolecules. Methylene glycol is the main product of the complete hydration of formaldehyde gas. Polymerization results in the development of paraformaldehyde as a result.

Formalin Chemical Properties

Formalin is a colourless liquid. Due to formaldehyde off-gassing, it has a strong, irritating odour. Since the PH of this solution is neutral, it can be used as a reducing agent to reduce other substances when making formic acid. Formalin solutions with a high concentration of formaldehyde are flammable. Since they can destroy dangerous microorganisms, this solution can be used as disinfectants and germicides. Aside from that, they have a dehydrating effect, the ability to preserve themselves, and the ability to combine with proteins, inactivating them and destroying cells. Formalin is widely used in aquariums to destroy parasites that live on fish because of these properties.


Synthesis of Formalin

  • When formalin reacts with a base, such as sodium hydroxide, sodium formate and methanol are produced. The chemical formula is shown below.


  • When formaldehyde reacts with ammonia, formamidine and water are produced. The chemical formula is shown below.

6HCHO + 4NH3 → (CH2)6N4 + 6H2O


Uses of Formelene

  • Formalin solution can be used as a disinfectant because it destroys most bacteria and fungi (including their spores). Toxins and viruses are inactivated using it as an ingredient in vaccine production. In personal care products like cosmetics, formaldehyde releasers are used as biocides. They are known to cause allergic contact dermatitis in some sensitized individuals, despite being present at levels that are not usually considered dangerous.

  • It's used to create resins like urea formaldehyde and phenol-formaldehyde, which are used in foundries to make cores and molds.

  • It's used as a disinfectant, fungicide, fumigant, and preservative in agriculture and medicine.

  • A broad range of products, especially building materials, contain formaldehyde.

Importance and Uses of Formalin

A carbon atom with an atomic number of 6has 4 electrons on its outer valence shell. So it can combine with many other elements and form different types of compounds. The number of types is so vast because carbon atoms can form chains by combining with each other. Hydrocarbons are the most famous among all the compounds formed by carbon. Hydrocarbons are the compounds formed by a combination of mostly carbon ( C ), Hydrogen (H) Oxygen (O), and some other less frequently combining elements such as Nitrogen (N), Sulphur (S), Phosphorus (P), etc. It is also interesting to note that because of such immense types of hydrocarbons found in nature and its importance in the working of nature these are studied in a whole separate branch of chemistry known as organic chemistry. 

In Organic Chemistry, we learn about different groups of hydrocarbons based on the type of bond they create while bonding with each other and forming chains. Examples are methane group, methylene group, methine group, etc. It also depends on the different types of substrates arched to the carbon chains. Aldehydes are one such group with Oxygen attached to one carbon atom at the end by a double bond. The first compound in this group formed by a single carbon atom bonded with two hydrogen atoms and one Oxygen atom is termed formaldehyde. It usually remains in a gaseous state at room temperature but can also be found dissolved in water. The water that contains dissolved formaldehyde is known as formalin. It is easily identifiable in laboratories due to its irritating smell or odor and is used as a disinfectant or germicide. 

FAQs on Formalin

1. What is the Function of Formalin?

As formalin is dissolved in water, it is used as an industrial disinfectant as well as a preservative in funeral homes and medical laboratories. It's also a preservative in certain foods and products like antiseptics, medications, and cosmetics.

2. Is Formaldehyde the Same as Formalin?

Formalin is another name for a formaldehyde aqueous solution, although the latter is preferred since formalin is still a brand name in some countries. Free formaldehyde is found in many disinfectants and antiseptics, as well as cosmetics, especially hair shampoos.

3. Is Formalin used to Preserve dead Bodies?

Formalin is a type of formaldehyde that causes cancer in humans. It is a disinfectant that is widely used in mortuaries to preserve dead bodies and also in science labs to preserve specimens of dead animals.

4. What is the Importance of Formalin?

Formalin is a chemical solution with a very strong and recognizable smell. It was first identified in the 1850s. Since then it has been used for various purposes. The most common use is as a disinfectant or germ killer in laboratories and industries. Also because it is a single carbon atom molecule so used for the formation of other molecules with a higher number of carbon atoms. Industries use this method to produce other complex organic compounds or substances such as urea-formaldehyde resin, melamine resin, phenol-formaldehyde resin, polyoxymethylene plastics among others. 

5. Why do Organic Compounds have a Separate Branch for their Study? 

By mass or weight, all the organic compounds that are present on earth are very less than the inorganic compounds or substances. But still, these compounds are of paramount importance because all the life forms that exist on earth are based on carbon in general and hydrocarbons in particular.  The organic compounds are formed from inorganic sources by the primary producers or plants. Plants intake carbon dioxide and water from the environment and combine it with the help of energy obtained from sunlight into glucose molecules which are also hydrocarbons or organic compounds. 

6. Is reading the Articles on the Vedantu Website Sufficient for Self-Studies?

A lot of students in India can't afford the facility of coaching institutes or tuition classes because that is becoming very essential day by day for the preparation of their academic studies. They have no other option other than doing it by themselves. Online websites are emerging increasingly to help such students immensely. At Vedantu we assist such students in every way possible. If you find any difficulty with solutions you can always search for the video explanation provided on this same website as well.

7. Are Class 12 Subjects Difficult to Understand and Remember?

When you enter Class 12 the subjects remain the same as the previous class but the chapters seem to be somewhat difficult to absorb. But the trick is to never get afraid or demotivated and start learning with patience. With time you will gradually complete all the courses and it will boost your confidence for appearing in the exams. If you stay sincere to your timetable and work hard to learn the fundamentals of the subject then any tough subject like Chemistry can be a scoring subject for you.

8. How to Secure Good Marks in Organic Chemistry?

Everything both living and nonliving has some chemical properties that depend on the building units of that substance. Atoms and molecules are the basic units of the construction of all substances. We study all about it in the subject of chemistry which has been broadly divided into 3 branches to make it easy for anyone studying Chemistry. Physical chemistry deals with the understanding of the structure and constituents of matter. In Organic chemistry, we learn about the presence of all types of carbon-based compounds and their properties. While in Inorganic chemistry we learn about the properties of all the substances other than the organic compounds. Among all Organic chemistry occupies the major portion of the chemistry syllabus in Class 11 and 12. The first step for learning organic chemistry appropriately is to remember the nomenclature or names of all the compounds mentioned in the book. It will help you to understand and remember the other chemical reactions in these chapters which are often asked in the question papers.