This document discusses various types of chemical bonds including the octet rule, ionic bonds, covalent bonds, and hydrogen bonds. It also explains valence shell electron pair repulsion (VSEPR) theory and how it is used to predict the three-dimensional shape of molecules. Some key examples covered include why O2 is paramagnetic while C2 is diamagnetic, why H2O exists as a liquid while H2S exists as a gas, and why the density of ice is less than that of water. The document also addresses why the LiBr bond is more covalent than the LiCl bond.

1. Chemical bond
by mohsin
By
Azim
khan

9. Octet Rule-

21. bond

22. ion

52. ozone

66. changes

142. Valence shell electron pair
repulsion (VSEPR) theory

143. VSEPR theory
Lewis dot structure fail to explain correct 3D shape of molecule.

144. VSEPR theory
state that
electron pair
repel each
other make
shape.

145. Example of VSEPR

156. Condition for combination of atomic orbital.
Both atom have same energy.eg. 1s orbit combine with 1s. 1s doesn't combine
with 2s.
Both atom have same symmetry .eg. 2Px orbit combine with 2Px. 2Px doesn't
combine with 2Pz.
Both atom have overlap.

157. O2 is paramagnetic while C2 is diamagnetic?
Paramagnetic substance are those which attract magnetic field. Paramagnetic
arise those ion, molecule which contain unpaired electron.
O = 1s2 2s2 2px
2 , 2P2
y, 2p1
z
Diamagnetic substance are those which repelled magnetic field. Diamagnetism
arise those ion or molecule which contain paired electron.
Unpaird electron
C = 1s2 2s2 2px
2

158. Hydrogen bonding
“Attractive force which bind H-atom to another electronegative atom.”
It is weaker then covalent bond.
H bond with other electronegative element like F,Cl,Br,O etc.

160. H2O exist as liquid while H2S exist in gas?
Electronegative of ‘O’ is higher then ‘S’.
Hence electronegativity of H2O is higher then H2S.
Hydrogen bond in H2O is stronger then H2S.
hence water is liquid and hydrogen sulphide is gas.

161. Density of ice is lesser then water.
At atmospheric pressure, ice is hexagonal form and low T become cube.
Ice has highly ordered 3D hydrogen bond structure.
Due to H-bonding ice get open structure with wide holes.
Therefore ice density lesser then water.

162. LiBr is more covalent bond the LiCl?
Br- anion is larger then Cl- anion.
Due to greater the size of anion stronger bonding.