Properties of Covalent Bond

A covalent bond is a type of chemical bond in which sharing of electron pairs between atoms takes place. The shared electron pairs are known as “bonding pairs” or “shared pairs”. When electrons are shared, a stable balance is created due to the attractive and repulsive forces between the atoms; this balance is known as covalent bonding. Due to sharing of electrons, many molecules attain a state that’s almost equivalent to an entire valence shell, thereby achieving a stable electronic configuration. Covalent bonds are a lot more common in chemistry than ionic bonds. Atoms having similar electronegativity have the greatest covalency. 

Covalent Bonds

Covalent bonds are formed when atoms, having similar electronegativity, share electrons. It’s important to note that each combining atom has to contribute at least one electron to the shared pair of electrons. As a result of sharing of electrons, each combining atom attains a noble gas configuration. So, when two combining atoms share one electron pair, they’re joined by a single Covalent Bond. Likewise, when two combining atoms share two electron pairs, they’re joined by double covalent bonds. Covalent bonds can be best understood by the example of the Chlorine molecule. Each chlorine atom contributes one electron to the shared pair, and in this process, both the atoms of chlorine attain the outer shell octet of nearest noble gas, i.e., Argon. 

Properties of Covalent Bonds

Covalent compounds are very diverse, so there are a lot of exceptions to the definition of covalent bonds. When you’re looking at any compound and trying to figure out whether it’s a covalent or ionic compound, it’s best to examine its properties. The properties of Covalent compounds are- 

• Most of the covalent compounds have comparatively low boiling or melting points.

In ionic compounds, ions are strongly attracted to each other. But this is not the case with covalent bonds. Covalent bonds create molecules which can easily separate from each other even when a lower amount of energy is added to them. Thus, these compounds have a relatively low melting or boiling point. 

• Covalent compounds generally have lower enthalpies of vaporization and fusion as compared to ionic compounds.

The amount of energy needed, at constant pressure, to melt one mole of a solid substance is known as the enthalpy of fusion. 

The amount of energy needed, at constant pressure to vaporize one mole of liquid is known as the enthalpy of vaporization. 

If we go by the average rate, then it takes only 1% to 10% heat to change the phase of a covalent compound as compared to ionic compounds. 

• Covalent compounds are relatively soft and flexible.

This is due to the fact that covalent bonds are relatively easy to break and are, therefore, flexible. In covalent compounds, the covalent bonds cause these compounds to take up the form of gases, liquids or soft solids. There is an exception when covalent compounds take up the crystalline form. 

• Covalent compounds are generally more flammable than ionic compounds.

Almost all flammable substances have Hydrogen and Carbon. When these substances undergo combustion, they release energy and react with oxygen to give out cardon dioxide and water. Since carbon and hydrogen have similar electronegativities, they’re often found together in many covalent compounds.

• Covalent compounds don’t conduct electricity when they’re dissolved in water. 

For the conduction of electricity in an aqueous solution, ions are required. Since covalent compounds dissolve into molecules instead of dissociating into ions, they don’t usually conduct electricity when they’re dissolved in water. 

Conclusion 

Covalent compounds are made up of bonds that are formed by sharing of electrons between atoms. Due to this sharing of electrons, these compounds exude some characteristic physical properties. Covalent compounds have comparatively low boiling or melting points and lower enthalpies of vaporization and fusion as compared to ionic compounds. These compunds are relatively soft and flexible and are generally more flammable than ionic compounds. Covalent Compounds don’t conduct electricity when they’re dissolved in water.