Formic Acid - Structure, Properties, Natural Occurrence, FAQs

Methanoic Acid structure

Formic Acid has a simple structure because it is the first carboxylic acid in the series and includes only one carbon atom, giving it the moniker methanoic acid. A carbon atom has a single bond with hydrogen, a double bond with oxygen, and another single bond with oxygen that is connected with a hydrogen atom in the structure.

Lewis structure of formic acid

Properties

Physical Properties

• The IUPAC designation for Formic acid is Methanoic acid. It is the first of the carboxylic acids in the homologous series.

• Formic acid seems to be a thick translucent liquid with no discernible colour, making it difficult to identify.

• Formic acid has a rather low melting point. The melting point of formic acid is only 8.4°C.

• Formic acid has a somewhat higher boiling point than water. Formic acid has a boiling point of 100.8°C.

• Formic acid has a low density of 1.22g/cm³ and is not a particularly dense liquid.

• Because formic acid is the first in the homologous series, its molecular weight isn't particularly high. Methanoic acid has a molecular weight of 46.03 g/mol

• The odour of formic acid is distinctively harsh and unpleasant.

• It is water soluble and miscible.

• Formic acid is colorless, flammable liquid with a sharp odor.

• It is soluble in hydrocarbons and miscible with water and most polar organic solvents

Chemical Properties

• Formic acid, as its name implies, is acidic and can convert blue litmus to red litmus

• Formic acid is a donor of hydrogen bonds. It is made up of hydrogen-bonded dimers rather than individual molecules in hydrocarbons and the vapour phase. The ideal gas law does not apply to gaseous formic acid because of its ability to hydrogen-bond. Solid formic acid is made up of a practically infinite network of hydrogen-bonded formic acid molecules that can exist in one of two polymorphs

• In most cases, formic acid comprises carbon and carbon types of covalent connections. Carbon forms all covalent bonds in formic acid as well. Only covalent bonds exist in formic acid

• Mercuric chloride can be reduced to mercurous chloride by formic acid, resulting in a white precipitate. The reaction's equation is shown below.

HCOOH + 2 HgCl₂ → Hg₂Cl₂ + 2HCl + CO₂

• With water, formic acid produces a high-boiling azeotrope (22.4 percent ). Formic acid in liquid form has a tendency to supercool.

• Formyl chloride, phosphoryl chloride, and hydrogen chloride are generated when formic acid reacts with phosphoric pentachloride. The equation is shown below.

HCOOH + PCl₅ → HCOCl + POCl₃ + HCl

Natural Occurrence

Formic acid can be found in most ants and stingless bees of the species Oxytrigona in nature. Formic acid can be sprayed by Formica ants on their prey or to defend their colony. When challenged by predators, the puss moth caterpillar (Cerura vinula) will spray it as well. It's also present in stinging nettle trichomes (Urtica dioica). Because of forest emissions, formic acid is a naturally occurring component of the atmosphere.

Manufacturing Processes for Formic Acid

Formic acid is produced by the following methods. Formamide is formed by reacting methyl formate with formamide.Methyl formate is generated when methanol and carbon monoxide combine in the presence of a strong base. Below is the chemical reaction to the above-mentioned procedure.

CH₃OH + CO → HCO₂CH₃

In industries, the procedure is also employed, and the reaction is carried out under particular conditions. The typical circumstances for the reaction's progress to be possible, are 80 °C temperature, 40 atm pressure,liquid phase.

Sodium methoxide is the most common base utilised in this method.The major result of hydrolysis of the obtained methyl formate is our target chemical. We also obtain various byproducts as a result of this. The following is the hydrolysis reaction

HCO₂CH₃ + NH₃ → HC(O)NH₂ + CH₃OH

2 HC(O)NH₂ + 2 H₂O + H₂SO₄ → 2 HCO₂H + (NH₄)₂SO₄

However, the approach described above has a drawback. The ammonium sulphate that is produced as a by-product of the reaction must be disposed of. Because the chemical is dangerous and can cause significant environmental harm, disposing of it is a time-consuming operation. Since numerous governments have restricted the disposal of chemicals into the environment in order to safeguard it, this has caused many manufacturers challenges.

Also Read:

• NCERT solutions for Class 12 Chemistry Chapter 12 Aldehydes, Ketones and Carboxylic Acids
• NCERT Exemplar Class 12 Chemistry Solutions Chapter 12 Aldehydes, Ketones and Carboxylic Acids
• NCERT notes Class 12 Chemistry Chapter 12 Aldehydes, Ketones and Carboxylic Acids

Formic Acid Uses

• In a fuel cell, formic acid can be employed (it can be used directly in formic acid fuel cells and indirectly in hydrogen fuel cells).Because it is unable to eliminate iron oxide deposits on its own, it is mixed with citric acid or HCl.

• Saturated monocarboxylic acids are used in a variety of industrial chemicals

• To reduce sodium and potassium dichromate, formic acid is used as a reducing agent.

• Useful in the dyeing and tanning industries, but other competitive acids have generally been cheaper, limiting the usage of formic acid to a few applications where it has distinct advantages.

• Formic acid is widely used in cattle feed as a preservative and antibacterial agent

• It is sometimes added to feed in the poultry business to destroy E. coli germs

• Because of its acidic nature, formic acid is also widely employed in the manufacturing of leather, including tanning (23 percent of global use in 2009) and dyeing and finishing textiles (9 percent of global consumption in 2009)

• Microbes can be used to manufacture isobutanol from carbondioxide by employing formic acid as an intermediate

• In reversed-phase high-performance liquid chromatography (RP-HPLC) analysis and separation techniques for the separation of hydrophobic macromolecules such as peptides, proteins, and more complicated structures such as whole viruses, formic acid is frequently utilised as a component of the mobile phase. Formic acid has various advantages over the more commonly used phosphoric acid, especially when combined with mass spectrometry detection.

Also check-

• NCERT Exemplar Class 11th Chemistry Solutions
• NCERT Exemplar Class 12th Chemistry Solutions
• NCERT Exemplar Solutions for All Subjects

NCERT Chemistry Notes:

• NCERT Notes Class 11th Chemistry
• NCERT Notes Class 12th Chemistry
• NCERT Notes For All Subjects