Covalent

In this article we are going to analyze is hydrogen bond stronger than Covalent or not.

A hydrogen bond cannot be stronger than a covalent bond. The bond energy of a covalent bond is 200 KJ/mole and the bond energy of a hydrogen bond is 8-42 KJ/mole.

Let’s have a closer approach towards the covalent bond, details and Facts.

Basically, a covalent bond is formed between a non metal and non metal by the process of mutual sharing of electrons.

Consider hydrogen atom

Image credit: Wikimedia

We know it has one atom and needs one more to satisfy its duplet, so what it does is shares its one electron with one more hydrogen atom. In this way through mutual sharing of electron pair the bond is satisfied and the so formed bond is a single bond (as only one pair of electrons are shared for bond formation).

Consider oxygen atom

We know that it requires 2 more electrons to achieve it octet. So one oxygen atom shares its pair of electrons with one more atom of oxygen. So in this way a double bond is formed.  Hence we can say that oxygen is an example of double covalent bond.

Consider nitrogen atom

We are aware that Nitrogen had 2,5 as its electronic configuration so in order to stabilize its octet it is in need of another three atoms.

So what it does is shares it electrons with more atom of nitrogen. This mutual sharing of electrons (3 pairs of electrons are shared) gives rise to triple bond. Hence it can be said that Nitrogen is an example of triple covalent bond.

Some Properties of Covalent bond in general:

• Covalent bonds (single, double, triple) are formed from molecules and not from ions.
• They are very bad conductors of electricity (as they do not have ions).
• They have very weak Vander Waal forces (i.e. intermolecular forces of attraction).
• They are quite weak in comparison to ionic bonds.
• They usually exist as gases, liquids and soft solids the reason being intermolecular forces of attraction.
• They have low melting point and low boiling point because of weak Vander Waal forces.
• Most of the times the liquid form is very volatile.
• Talking about the solubility it depends whether the covalent compound is :

1. Polar
2. Non-Polar

Non-Polar Covalent bonds:

They do not conduct electricity and are insoluble in water. Basically they have all the general properties of general covalent bonds.

Polar Covalent bonds:

To understand the concept of Polar Covalent bonds let’s have a look at the example of HCl.

Chlorine is electronegative so it will pull electron pair towards itself. So partial positive charge will be developed on hydrogen and partial negative charge will be developed on the chlorine (this charges are very minimal, so electrons are shared but not equally by both). So this kind of compounds which have difference in the electronegativity have polarity and ate called as polar compounds.  This compounds are generally most of the times soluble in water, conduct electricity (as they have some amount of charges present).

Let’s analyze hydrogen bonding:

A hydrogen bond is the type of bonding where a hydrogen atom is attached to a covalently bonded atom (which should be electronegative in nature) and also attached to one more electronegative atom.  This bond is the hydrogen bond or hydrogen bonding.

Some Properties of Hydrogen bonding:

• As temperature increases hydrogen bonding strength decreases.
• It has around five to ten percent ionic nature.
• Consider hydrogen bonding in molecule of H2O which has three different states:
• Taking into account solid which is ice has a temperature of around less then or equal to zero degrees Celsius.  It has four hydrogen bonds.
• Taking into account liquid, which has a temperature of around zero to four degrees Celsius. It has two hydrogen bonds.
• Taking into account gas, which has a temperature greater or equal to four degrees Celsius. It exists usually in vapor or steam form. It has no hydrogen bond.
• As the electronegativity increases the strength of hydrogen bond also increases.
• Have you ever wondered why alcohol does not dissolve in water? The reason for this is that alcohol forms hydrogen bonding with water. Hydrogen bonding is formed between partial positive hydrogen atom of alcohol and partial negative end of oxygen of water.

For complete details about hydrogen bonding refer: Is Peptide Bond A Hydrogen Bond: Why, How, Detailed Facts

Why Covalent bond is stronger than hydrogen bond?

We know that the bond energy of hydrogen bonding is very less as compared to that of covalent bond (bond energy of hydrogen bonding is 8-42 KJ/mole and covalent bond is 200 KJ/mole).

Also the covalent bond has shorter bond length in comparison to the hydrogen bond (it has quite longer bond length). We know that bond length and the bond strength are related in inverse manner meaning the two quantities are inversely proportional to each other. Covalent bonding short bond length will have more strength hence covalent bonding is stronger than hydrogen bonding.

Read more about: 15+ Limiting Reactant Problems: And Solutions

Are hydrogen bonds stronger than non polar covalent bonds?

As we have seen in the above section that non polar covalent bonds are the ones which are bad conductors of electricity, possess weak Vander Waal forces, have low melting point and low boiling point and are insoluble in water.

On the other side we can see that hydrogen bonding can conduct electricity, is stronger than Vander Waal forces, has high melting point and high boiling point. We can conclude that covalent bonding and hydrogen bonding both being chemical bond , covalent bond is always stronger than hydrogen bond ( as it is formed as a result of mutual sharing of electrons).

Hence non polar covalent bonds are stronger than hydrogen bonding.

Read more about: 5+E1 Reaction Example: Detailed Explanations

Hydrogen bond v/s covalent bond

Hydrogen Bonding	Covalent Bonding
Hydrogen bonding involves dipole-dipole kind of attraction.	Covalent bonding involves mutual sharing of electrons between atoms.
Has the ability to conduct electricity	Does not have the ability to conduct electricity
Have higher melting point and higher boiling point.	Has comparatively lower melting point and lower boiling point
Are seen to be stronger than Vander Waal forces.	Are weaker Vander Waal forces
Bond energy is around 8-42 KJ/ mole.	Bond energy is 200 KJ/mole.

Also Read:

• Is peptide bond covalent

In this article, ”Is peptide bond covalent ” the covalent or the ionic character of peptide bond is discussed briefly.

Peptide bond, a very essential linkage in the primary structure of protein , is formed between two alpha amino acids and plays an important role construct protein, a macromolecule.  This formation of peptide bond is classified as condensation reaction because one water molecule (H2O) is eliminated from the reaction medium.

Some frequently asked questions about the covalency of the peptide bond are pointed out specifically in this article.

Is Peptide Bond Covalent

Peptide bond is a well known chemical covalent bond in chemistry.

Peptide bond links two amino acids, very specifically it can be described that peptide bond is the linkage between alpha amine group (NH2) and alpha carboxylic acid group (COOH) coming from two same or two different amino acid.

After elimination of water molecule peptide bond is formed and it is basically an amide (CONH₂) type linkage between two consecutive alpha amino acid.

Peptide bond possesses a partial double bond character of C-N bond due to delocalisation of unshared pair of electrons coming from nitrogen into the carbonyl group (C=O). Thus peptide bond attains a planar geometry and sp² hybridisation.

The above resonance structure and the explanation can describe that why peptide bond is a covalent bond.

To know more please check: Peptide bond formation: How, Why ,Where ,Exhaustive Facts around it

Are All Peptide Bonds Covalent?

 In Chemistry, all peptide bonds are amide type strong chemical covalent bond.

The main criteria to be fulfilled to form a covalent bond is sharing of valence electrons between the participating atoms. These electron pairs are called as bonding electron pairs. The driving force of the formation of covalent linkage is the electrostatic attraction of the participating nuclei for the electrons.

Peptide bonds generally bind the acid end of one alpha amino acid with the amino end of the next amino acid.

Peptide linkage is a strong covalent linkage that connects two amino acids and eliminates one water (H₂O) molecule. One hydrogen atom from amine group (NH₂) and OH from carboxylic acid group (COOH) is eliminated as water (H₂O).

To know more please follow : Is HBr Ionic or Covalent : Why? How, Characteristics and Detailed Facts

 

Peptide Bond Covalent Characteristics

There are some characteristics of covalent peptide bond, described below-

Peptide bonds are strong, rigid and planar. Peptide bond is not flexible and free rotation about this bond is become restricted. This bond possesses some double bond character due to sharing of unpaired electrons, which is one of the main characteristics of covalent linkage.

Peptide bond also contains partial positive charge for the presence of polar hydrogen atoms of amino group and partial negative charge due to presence of polar oxygen atoms come from carboxylic acid group.

Due to the resonance stabilization, peptide bond basically remains unreactive under physiological conditions, even they are also less reactive with comparing to their almost similar compounds, ester.

To know more please check: Peptide Bond vs Ester Bond: Comparative Analysis And Facts

Why Peptide Bond is Covalent Bond?

The definition of ionic bond and covalent bond is discussed below-

Electrostatic attraction between the oppositely charged (positively charged and negatively charged) molecules is the main criteria to form an ionic bond. Thus it is called an electrovalent bond. In the formation of ionic bond, the valance electrons from the more electronegative atoms are permanently transferred to the more electropositive atoms.

Ionic compounds generally have higher and sharp melting and boiling point but peptides have melting point in the range between 25⁰ to 113⁰ celcius. Thus peptides are not melted in a particular temperature.

From the above explanation it is clear that peptide bond does not execute any ionic compound character rather it shows covalent character like any other covalent compound.

To know more please follow: Peptide Bond vs Disulfide Bond: Comparative Analysis and Facts

Why Is Peptide Bond Not Ionic

There is a basic difference between the characteristics of covalent bond and an ionic bond.

The main difference between these two bonds is in their formation process. Permanent transfer of electrons between the atoms have to be fulfilled to form an ionic bond . whereas covalent bond is formed due to sharing of electrons between the atoms. The extent of sharing the electrons in covalent bond may not be equal and it depends upon the electronegative character of the atoms.

Peptide bond is formed due to sharing of electron pairs come from nitrogen to the carbon nitrogen bond known as peptide bond and achieves a partial double bond character and a rigid and planar structure.

Peptide bond gets extra stability due to this resonance and resonance stabilization cannot be achieved by any ionic bond. Resonance stabilization is an important stabilization factor of covalent bond.

All these discussion indicates that peptide bond is definitely a covalent bond, not an ionic bond.

Some frequently asked questions about the peptide bond is discussed below-

Frequently Asked Questions (FAQ)

How Peptide bond can be broken?

Answer: Peptide bond can be broken by hydrolysis. Amide type linkage is hydrolysed by adding of water and give two constituent amino acid residue.

Are Peptide bonds strong or weak?

Answer: Peptide bond is an example of strong covalent bond with a high bond dissociation energy.

Why peptide bond is covalent bond?

Answer: Peptide bond is formed due to sharing of electrons between carbon and nitrogen and this is one of the most important characteristics of an covalent bond.

Also Read:

• Is hydrogen bond stronger than covalent