Difference Between Formamide and Formaldehyde

The key difference between formamide and formaldehyde is that the formamide is an amide, but the formaldehyde is an aldehyde.

Formamide and formaldehyde are important organic compounds. Both these compounds have their functional groups attached to a hydrogen atom. Therefore, formamide has an amide group attached to a hydrogen group, and formaldehyde has a carbonyl group attached to a hydrogen atom. Moreover, these are the smallest members of each compound series; i.e. formamide is the smallest compound among aliphatic amides while formaldehyde is the smallest member of the aldehyde group.

CONTENTS

1. Overview and Key Difference
2. What is Formamide 
3. What is Formaldehyde
4. Side by Side Comparison – Formamide vs Formaldehyde in Tabular Form
5. Summary

What is Formamide?

Formamide is the simplest aliphatic amide having the chemical formula HC(=O)NH₂. This is an amide that forms from formic acid. This compound exists as a clear and oily liquid that is miscible with water. Moreover, it has an ammonia-like odour. Its molar mass is 45 g/mol. The melting point is very low (2 to 3 °C), but the boiling point is high (210 °C).

In the past, formamide was produced by treating formic acid with ammonia. Here, this reaction produces ammonium formate, and upon heating, it gives formamide. However, the modern method of production involves the carbonylation of ammonia.

There are several applications of formamide. One of the main uses is as the feedstock for the production of sulfa drugs and many other pharmaceuticals. It is also important in gel electrophoresis as an RNA stabilizer.

What is Formaldehyde?

Formaldehyde is the simplest aldehyde. Its chemical formula is CH₂O, and IUPAC name is Methanal. Moreover, the molar mass of formaldehyde is 30 g/mol. Also, at the room temperature and pressure, formaldehyde is a colourless gas. Besides, it has a pungent, irritating odour.

Furthermore, the melting point of formaldehyde is −92 °C, while the boiling point is −19 °C. Formaldehyde contains a carbon atom, two hydrogen atoms and an oxygen atom bonded to each other via covalent chemical bonds. The shape of the molecule is trigonal planar.

Formaldehyde aqueous solution is flammable and corrosive. When preparing a formaldehyde solution, methanol is added to prevent formaldehyde from precipitating as paraformaldehyde. In cold conditions, formaldehyde tends to form cloudiness in the solution due to the formation of macromolecules via formaldehyde polymerization.

There are many applications of formaldehyde in industries and other areas. It is used as a precursor for many organic synthesis processes; for example, resins such as melamine resin, phenol-formaldehyde resin. Apart from that, it is used as a disinfectant. It can kill bacteria and fungi on wood surfaces. However, formaldehyde is toxic and known to be carcinogenic.

What is the Difference Between Formamide and Formaldehyde?

Formamide and formaldehyde are important organic compounds. Both these compounds have their functional groups attached to a hydrogen atom. The key difference between formamide and formaldehyde is that formamide is an amide, whereas formaldehyde is an aldehyde. Also, formamide is the simplest aliphatic amide and has the chemical formula HC(=O)NH₂ while formaldehyde is the simplest aldehyde with the chemical formula CH₂O.

There are many applications of formamide. Some important ones include the use of it as a feedstock for the production of sulfa drugs and many other pharmaceuticals, production of hydrogen cyanide, and RNA stabilizer in gel electrophoresis. Formaldehyde, on the other hand, is used as a precursor for many organic synthesis processes; in resins, such as melamine resin, phenol-formaldehyde resin, etc.

Below infographic summarizes the difference between formamide and formaldehyde.

Summary – Formamide vs Formaldehyde

In brief, formamide and formaldehyde are important organic compounds. Both these compounds have their functional groups attached to a hydrogen atom. However, the key difference between formamide and formaldehyde is that the formamide is an amide, but the formaldehyde is an aldehyde.

Reference:

1. “Formamide.” Wikipedia, Wikimedia Foundation, 20 June 2019, Available here.
2. “Formamide.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.

Image Courtesy:

1. “Formamide-2D” (Public Domain) via Commons Wikimedia
2. “Formaldehyde-2D” By Wereon – Own work (Public Domain) via Commons Wikimedia