ChemistryRythm

VALENCE BOND THEORY :    Introduction       Salient Features of  VB theory Types of overlapping Different Between Sigma Bond and Pii Bond  a. INTRODUCTION:        Valence bond theory was introduced by Heitler and London (1927) and later it was developed further by Pauling and others.     A discussion of the valence bond theory is based on the knowledge of atomic orbitals, electronic configurations of elements , the overlap criteria of atomic orbital s and the principles of variation and superposition .     ATTRACTIVE FORCE   REPULSIVE FORCES ·          Nucleus of H a and valence electron of  H b.   ·         Nucleus of H b and the valence electron of H a.   The nucleus of H a and H b .  ·        ...

FANJAN’S RULE   : Fanjan’s Rule: Introduction      Factor favoring polarization    Application of polarization.  INTRODUCTION:       Ionic and covalent bonds are the two extreme type of bonding and almost always the bonds formed intermediated type. This is explained in the term of polarizing power of the cation and polarizabilit y of the anion and the shape of the ions. Fanjan’s rule in inorganic, formulated by Kazimier Fajan in 1993. Fanjan’s rule can be used to predic t whether a chemical bond is expected to be predominately ionic or covalent and depend on the relative charges and sizes of the cation and anio n. IONIC   COVALENT  Low positive charge  High positive charge  Large cation  Small cation  Small anion  Large anion  The scientist, Fanjan introduced mainly four important ru...

POLARIZATION OF IONS: 1.1. INTRODUCTION:   If two oppositely charged ions are brought tighter, the nature of the bond between them depends upon  the effect of one ion on the other .      If the degree of polarization is quite small , an ionic bond is formed, while if the degree of polarization is larger , a covalent bond result.      The ability of a cation to distort an anion is known as its polarization power and the tendency of the anion to become polarized by the cation to become polarized by the cation is known as its polarizability  The two identical atom have equal tendency to attract the shared pair of electron and hence the shared pair of electron lies exactly in the middle of the nuclei c of two atoms.      However, in the case of covalent bond formation between atoms having different electronegativity, the atom with higher electronegativity will have grater tendency to attract the shared pair of elect...