Chemical Bonding And Molecular Structure

- Confused? Not any more, understand most confusing terms of the chapter in a very easy method.
1
A polar covalent bond always means 50% ionic and 50% covalent characteristics. No. The percentage ionic character in a covalent molecule is mostly dependent on the difference in electronegativity between the bonding atoms. Also, the greater the electronegativity difference, higher is the ionic character in a covalent molecule. So, the percentage ionic character in a covalent bond can vary anywhere between 0 and 100.
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2
Decoding the terms Lattice enthalpy and Bond enthalpy Both the terms are related to the amount of energy requires to break one mole of a chemical compound. So, can these terms be used interchangeably? Bond enthalpy usually refers to the amount of energy required to break a covalent bond. While lattice enthalpy refers to the amount of energy required to dissociate one mole of an ionic compound into its constituent gaseous ions. So, we have to be careful while using these terms in our chemistry course.
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3
Resonance
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When one Lewis dot structure is not enough to represent a molecule, we draw out separate structures like in the image above. It may seem that such a molecule flips between these different resonating structures. But in reality, a molecule such as an ozone do not have separate structures. It exists as a single entity, where none of the resonating structures can completely define the actual molecule. Resonance can be thought of as a human invention to solve the limitations in representing the bonding of certain molecules.