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Chemical Bonding and Molecular Structure

Long Answer Type

141.
Discuss the formation of compounds in which octet rule is violated.

There are some exceptions to the octet rule:

(i) Formation of compounds like BeCl₂, BF₃ AlCl₃ etc. In each of these molecules, the central atom (Be, B or Al) has less than 8 electrons i.e. these are electron deficient compounds.

(B and Al have 6 electrons around them.)

(ii) Formation of compounds like PCl_3, SF₆, IF₇ etc. In each of these molecules, the central atom has more than 8 electrons.

The octet rule is violated in these molecules.

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142.

Discuss the Modern(or Quantum) Theory of covalent bond.

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143. Explain the formation of H₂ molecule on basis of valence bond theory.
Or
In the light of attractive and repulsive forces, show that a molecule of hydrogen is formed.

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144. In the light of attractive and repulsive forccs, show that helium molecule is not formed.

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145.

What are general characteristics of covalent compounds?

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146.

Give the comparison between electrovalent and covalent bonds.

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147.

Give the comparison between Electrovalent (or ionic compounds) compounds and covalent compounds (special reference to properties).

220 Views

148.

Discuss the orbtial concept or quantum concept for the formation of covalent bond.
Or
Explain the formation of covalent bond on the basis of valence bond theory.

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