Property of covalent bond???
Answers
Answer:
Bond Length:
Formation of bond between two atoms does not bring the two atoms very close to each other. There will be certain distance between the two atoms involved in the bond formation. That average distance between the nuclei of the two atoms is termed as bond length or bond distance. It is measured in terms of angstrom units, where 1 Aο = 10-8 cm. Formation of multiple bonds between atoms reduces the bond length. Another reason for decrease in bond length in involvement of s-orbitals that are smaller in size compared to p-orbitals. Factors such as electronegativity, hybridization and steric effects do have influence on the bond length.
Bond Energies:
It is the amount of energy liberated or consumed when a covalent bond is broken or formed. Every bond has its own unique bond energy values. Generally, bond dissociation energy is used to state the strength of the bond. Greater the bond dissociation energy, greater will the strength of the bond and more stable will be the compound. In compounds with multiple bonds, bond dissociation energy is the sum of the bond dissociation energies of the same type of bonds present in the molecule.
Bond energy increases with the formation of multiple bonds. Hence, compounds with triple bonds are more stable than those with single bond. In case of sigma bond and the pie bond, sigma bond is stronger. Another factor affecting the bond energy is the presence of lone pair of electrons. Bond energy decreases with the increase in the number of lone pair of electrons. Hence, among C-C, N-N, O-O, O-O has lower bond energy due to the presence of more number of lone pair of electrons compared to the other two. The reason for lowered bond energy in compounds with a lone pair of electrons is due to the presence of electrostatic repulsion between the lone pair of electrons.
Bond Angles:
The average angle between the bonded orbitals is termed as bond angle and is represented as θ. Due to the movement of the molecules, the bond angle keeps changing. Hence, the bond angle of a molecule is taken as an average of these angles. Bond angle is greatly determined by the orbitals involved in the bond formation. For example, the compounds with bonds formed by p-orbitals have a bond angle of 90ο. However, all bonds formed involving p-orbitals do not have the above mentioned 90ο. This is due to the action of various forces such as repulsion between atoms or groups attached to the central atom, hybridization of bonding orbitals and the repulsion due to presence of lone pair or non-bonding electrons.
For example in case of H-S-H the bond angle is 92ο 26 instead of the regular 90ο.This is due to the presence of repulsion between hydrogen atoms attached to the central sulphur atoms.
Similarly, the bond angle of water molecule is 105ο instead of the regular 90ο due to the presence of lone pair of electrons on the oxygen atom.
Answer:
Covalent compound are usually solid, liquid or gas.
Covalent Compound have low melting and low boiling point
It is usually insoluble in nature but solube in organic solvent
they don't conduct electricity.