Intermolecular Forces of CH3OH (Methanol)

Methanol is a natural product. It is the first member of the saturated alcohol homologous series.

It’s a colourless, volatile liquid with a distinct odour that dissolves in water.

In 1661, Robert Boyle used wood to distil pure methanol for the first time.

It’s frequently employed as a polar solvent and in the manufacture of other compounds.

Syngas is used to make methanol in industrial settings. Microbes, vegetation, and volcanic gases all produce it naturally.

The notion of intermolecular forces will be explored in this article, as well as the intermolecular forces for methanol.

So, in methanol, what are the intermolecular forces? Methanol interacts with other molecules via hydrogen bonding, which occurs when the hydrogen atom has a considerable positive charge as a result of its interaction with a strongly electronegative oxygen atom. The London forces are also there, but their role is minor.

There’s a lot more to learn about methanol’s intermolecular forces. Let’s take a closer look at the chemistry underlying it in the following subheadings.

Why is hydrogen bonding present in methanol (CH3OH)?

Methanol is a polar molecule with a dipole moment that is constant.

H is linked to O, which is extremely electronegative, in methanol. Because hydrogen creates a partial positive charge and oxygen develops a partial negative charge, hydrogen bonds with the oxygen atom of another methanol molecule.

One methanol molecule creates three hydrogen bonds, two through the oxygen atom (as a proton acceptor) and one through the hydrogen atom (as a proton donor) (as proton donor).

Are London Dispersion Forces present in methanol (CH3OH)?

Methanol interacts with London forces in addition to hydrogen bonds, however the magnitude of London forces is significantly smaller than hydrogen bonds.

With the lengthening of the carbon chain, the contribution of London forces grows.

In the case of methanol, London forces are frequently overlooked.

What are Intermolecular Forces and How Do They Work?

Matter is commonly classified as solid, liquid, or gas. They exist in these varied forms for a variety of reasons. Intermolecular forces are one of the explanations.

Attractive or repellent forces exist. When the attraction force is substantially stronger than the repulsion force, molecules are strongly attracted to one another and form a solid. It exists as a gas when the repulsion force is larger than the attraction force. In intermediate conditions, a substance exists as a liquid.

We’ll talk about attractive forces in this essay. Intermolecular forces are the forces that hold a substance’s molecules together. Intermolecular forces are important for keeping molecules together in solids and liquids.

In nature, no atom or molecule exists in isolation; intermolecular forces interact with surrounding molecules.

The physical qualities of a substance are determined by the type of forces present. If the forces are strong, for example, the melting and boiling points will be high because more energy will be required to dissolve their bond.

Intermolecular Forces Types

The magnitude of charges determines the strength of intermolecular forces. The attraction between positively charged and negatively charged components causes these intermolecular forces.

Because methanol interacts through Van der Waals forces, we shall go through them in depth.

Interaction of ions

Because full charges are present on the atoms in ions, the force is stronger than it is in neutral polar and non-polar compounds.

An ionic compound causes polarity when it comes close to a neutral compound.

Ion-dipole forces interact with the side near the ionic compound, which creates an opposing charge.

Interaction of Van der Waals

Van der Waals forces are attractive intermolecular forces that are proportional to the inverse sixth power of the spacing between molecules. The following are the different types of Van der Waals forces:

• Dipole-dipole forces– These forces exist between substances that have a constant dipole moment.

The dipole’s ends have partial charges with opposing signs. When a polar molecule approaches another polar molecule, dipole-dipole forces engage between the ends with opposite charges.

When two HCl molecules are brought closer together, the Cl side (partial negative) of one attracts the H side (partial positive) of the other through dipole-dipole forces.

• Hydrogen bonding– This is a type of dipole-dipole interaction that is unique.

Hydrogen bonding, for example, is used to interact between water molecules.

• A dipole-induced dipole is a force that exists between polar and nonpolar molecules.

A polar molecule develops a dipole by developing partial charges.

When this polar molecule approaches the non-polar molecule, the non-polar molecule’s electron cloud is deformed, causing partial charges to form. An induced dipole is formed when a non-polar molecule gets polarised. Dipole-induced dipole forces are the attraction between a polar molecule and an induced dipole.

The interaction between polar HCl and non-polar Ar atoms, for example, is dipole-induced dipole type.

• London forces– All molecules are affected by this type of force. It is the most vulnerable of the Vander Waals forces.

Non-polar molecules are symmetrical and can create a dipole moment for a short time.

A adjacent non-polar molecule gets an instantaneous dipole moment when the electronic distribution of a non-polar molecule changes momentarily.

The London or dispersion force is the attraction between two non-polar molecules.

The London forces, for example, govern the interaction between methane molecules.

This form of intermolecular force can be seen in methane (CH4). Examine the intermolecular force of CH4.

Hydrogen Bonding is a type of chemical bonding.

H should be attached to a highly electronegative element that creates a partial negative charge, while hydrogen develops a partial positive charge, for hydrogen bonding to occur. Through hydrogen bonding, another electronegative atom from a different or the same molecule connects with H.

For hydrogen bond formation, the ideal bond angle is 180°. The strength of the hydrogen bond weakens as the angle is changed.

It’s the most powerful Vander Waals force.

It is an electromagnetic interaction between partial negative and partial positive charges, not true bonding.

The many qualities of a substance are determined by hydrogen bonding. Because of hydrogen bonding, lower alcohols like methanol are soluble in water.

Because of hydrogen bonding, water is a liquid, but hydrogen sulphide is a gas.

Hydrogen bonding can be divided into two categories.

• Intramolecular (intermolecular) When hydrogen bonds form between atoms in the same substance, this is known as hydrogen bonding.

• When hydrogen bonds between atoms or molecules of different substances, this is known as intermolecular hydrogen bonding.

Water or Methanol have stronger intermolecular forces of attraction.

Hydrogen bonding is used by both water and methanol to interact with other molecules of the same type.

Methanol can make hydrogen bonds with three other methanol molecules, whereas water can only form hydrogen bonds with four other water molecules.

As a result, water has a stronger hydrogen bonding than methanol, resulting in larger intermolecular forces of attraction.

Intermolecular and intramolecular forces are compared.

The force between two molecules is referred to as an intermolecular force of attraction or repulsion. Because of intermolecular forces of attraction (hydrogen bonding) between various water molecules, water exists as a liquid.

The force that holds one molecule together is known as intramolecular force.

As an example,

In methanol, the intramolecular force is the covalent link between C and H, C and O, and O and H, which holds the molecule together.

Hydrogen bonding and dispersive forces between two methanol molecules act as intermolecular interactions in methane.

Methanol’s Polarity

The existence or absence of a net dipole moment determines a compound’s polarity. The net dipole moment is influenced by

• The bond’s dipole moment.

• The electronegativity differential between the atoms forming a link.

• Aesthetics, symmetry, and geometry

Methanol is a polar molecule, right? | Socratic method There is a difference in electronegativity because all bonds are generated between different elements. C, H, and O have electronegativity values of 2.55, 2.2, and 3.44, respectively. As a result, all of the bonds are polar.

Polar bonds, on the other hand, do not guarantee a polar molecule. Methanol has a tetrahedral form, but it is not symmetrical since it has three -H bonds and one -OH bond. As a result, the dipole moments do not cancel out, and the molecule is polar.

It has the ability to form both positive and negative poles.

I’ve also created an article about whether methanol is polar or nonpolar.

In Methanol, bonding occurs (CH3OH)

Because the difference in electronegativity of the atoms forming a bond is insufficient, it is a covalent molecule.

Both O and C are sp3 hybridised in methanol.

Hybrid orbitals develop when the 2s and 2p orbitals in C collide. Three of them overlap with hydrogen’s 1s orbital, while the fourth overlaps with O’s sp3 hybrid orbital.

The 2s and 2p orbitals overlap in O, forming hybrid orbitals. Two-hybrid orbitals have a lone pair, one of which overlaps with hydrogen’s s orbital and the other with C’s sp3 hybrid orbital.

Methanol has a tetrahedral shape because it is a type AX4 molecule with four side atoms and no lone pairs.

Check out the CH3OH Lewis Structure, Hybridization, and Geometry article.

Methanol’s Applications (CH3OH)

• It’s used to make formaldehyde and acetic acid, among other compounds.

• It is used in autos as an antifreeze.

• It’s used to power rockets.

• It is extensively used as an organic solvent in laboratories.

• It’s a chemical that’s employed to render industrial ethanol unfit for human consumption.

• It’s found in televisions and cell phones.


Through hydrogen bonding and London dispersive forces, methanol interacts with another methanol molecule.

Through hydrogen bonding, one methanol molecule can interact with three additional methanol molecules.

In comparison to hydrogen bonding, London forces are insignificant.

Intermolecular forces have a strength that is proportional to their order.

Ion-ion > ion-dipole > hydrogen bond > dipole-dipole > dipole-induced dipole > induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced dipole-induced

Intramolecular forces hold atoms in a molecule together, while intermolecular forces hold different molecules together.

Methanol is a polar molecule with a dipole moment that is constant.

The geometry of methanol is tetrahedral, and C and O are sp3 hybridised.

In the laboratory, methanol is a very valuable substance.

Good luck with your reading!

Read more: Is It Possible for Gasoline to Freeze?

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.


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