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Linear combination of atomic orbital, Molecular orbital theory, Difference between bonding & anti bonding moleculer orbital.

Linea combination of atomic orbital  molecular orbital are formed by combination of atomic orbital  if ꌏ(A)  andꌏ(B)  are the wave function of atomic orbital of two combining atomic A and B  then according  to Linea combination of atomic orbital, these two wave function can be added or can be substracted .that means there are two modes of interaction (symmetric and antisymmetric)  We know ꌏ(s)  = ꌏ(A) +ꌏ(B)  ꌏ(a) = ꌏ(A)- ꌏ(B) ꌏ(s)  and ꌏ(a)  represent wave function of bonding and antibonding moleculer orbital. the formation of moleculer orbital ꌏ(s)  and ꌏ(a)  from two atomic orbital ꌏ(A) and ꌏ(B)  is represented as Molecular orbital theory (MO)  theory: main points of mo theory are: 1.whwn atomic orbital combine they formed molecular orbital. 2.Number of molecular orbital formed is equal to number of atomic orbital combine. 3.atomic orbital are uninuclear  while molecular orbital  are polynuclear. 4.The various molecular orbital are arranged in order of in increas
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shape of compounds due hybridisation

shape of compounds due hybridisation 1.Shape of sncl2 (stannois chloride) Ground state Sn (50)  5s^2 5px^1 5py^1 5pz^0 since sp^2 hybridisation takes place so sncl2 molecule should be triangular or triginal planar but actually sncl2 molecule is Bent because ane position of triangle is occupied by lone pair of electron. 2 shape of ClO4(perchlorate) Ground state Cl (17)   3s^2 3px^2 3py^2 3pz^1 3d^0 excited state           3s^2 3px^1 3py^1 3pz^1   3d^3            { sp3 hybridisation }      {π bond} orbital formed π bond don't take part in hybridisation .since sp3 hybridisation take place . so ClO4 is tetrahedral. 3.Shape of ClO3^-(chlorate ion) Ground state Cl (17)  3s^2  3px^2 3py^2 3pz^1 3d^0 excited state           3s^2  3px^1 3py^1 3pz^1 3d^2           { sp3 hybridisation}    {2π bond} since sp3 hybridisation takes place .so clo3^-should be tetrahedral. but actually clo3^- is pyramidal .because one position of tetrahedral occupied by lone pair of elec

Shape of compounds due hybridisation

Shape of compounds due hybridisation 1.Shape of IF7 ( iodine hepta fluoride) Ground state I (53)    5s^2 5px^2 5py^2 5pz^1 5d^0 excited state            5s^1 5px^1 5py^1 5pz^1 5d^3              {     sp3d3 hybridisation          } since sp3d3 hybridisation takes place .so IF7 molecule is pentagonal bipyramidal. bond angles 72° &  90°. 2.shape of NH3(Ammonia) Ground state N (7)   1s^2 2s^2 2px^1 2py^1 2pz^1          {sp3 hybridisation} since sp3 hybridisation takes place. so NH3 molecule should be tetrahedral. but actual NH3 molecule pyramidal. because one position of tetrahedral occupied by lone pair of electron. Due to lone pair -bond pair repulsion bond angle decrease from 109°28' 3.shape of H2O(Water) Ground state (H)  1s^2 2s^2 2px^2 2py^1 2pz^1                { sp3 hybridisation} since sp3 hybridisation takes place so H2O molecule should be tetrahedral is V shaped (bent shaped)  because two positions of tetrahedral are occupied by lone pair

shapes of many compounds due hybridisation

shapes of many compounds due hyberdisation 1.shape of BF3 (boron trifluoride) Ground state  B (5)    1s^2  2s^2  2px^1  2py^0 2pz^0 excited state     1s^2  2s^1  2px^1  2py^1  2pz^0                 { sp2 hybridisation} since sp2 hybridisation takes place. so BF3 molecule triangular with bond angle 120° triangular or trigonal planer 2.shape of CH4 (Methane) Ground state  C (5)    1s^2  2s^2  2px^1  2py^1 2pz^0 excited state     1s^2  2s^1  2px^1  2py^1  2pz^1                 { sp3  hybridisation} since sp3 hybridisation takes place. so CH4 molecule tetrahedral with bond angle 109°.28' 3. shape of PF5 (phosphorus pentafluorine) Ground state  P (15)    3s^2  3px^1  3py^1 3pz^1 3d^0 excited state           3s^2  3px^1  3py^1  3pz^1  3d^1                       { sp3d hybridisation} since sp3d hybridisation takes place. so PF5 molecule is tringonal bipyramidal. equitorial 120° axial 90° axial bond are slightly larger than equatorial bond b

Hybridisation, types of hybridisation and it's conditions

Hybridisation:  the phenomenon of intermining of various orbital which differ slightly in energy to give rise to new orbital of indentical energy is called hybridisation. hybrid orbital form stronger covalent bond because they are more directional. types of hybridisation: depending upon the no.  and type of hyberdisation, hybridisation can be of sp, sp^2, sp^3, sp^3d, sp^3d^2, sp^3d^3. conditions for hybridisation: 1.orbital valence shell take part in hybridisation 2.orbital taking part in hybridisation should be of almost same energy. 3.orbital forming π bond do not take part in hybridisation. shape of compounds 1.Shape of BeF2 (beryllium dichloride) ground state    Be    (4)    1s^2 2s^2 2px 2py 2pz excited state    Be     1s^2 2s^1 2px^1 2py 2pz                      { sp             } since sp hybridisation takes place beF2 molecule is linear with bond angle 180°                      

Section B Chapter 1 covalent bond

Covalent bond: the bond which is formed by mutual sharing of electron is called covalent bond. this bond made by only non-metal by sharing. Ionic bond : the bond which is formed by permanent displacement of electron is called ionic bond. this bond made by only metal and non-metal. Factors favouring covalent bond: 1.high ionisation . 2.high electro affinity and high electronegativity. 3.high nuclear charge. 4.valence shell having 5,6,7 electron. characteristic of covalent compound: 1.melting point and boiling low: covalent compound have low melting point and boiling point because little energy is required to break weak intermolecular force. 2.Solubility: covalent compounds are generally soluble in organic solvent like benzene. 3.physical state: covalent compound can exist as gas due to the presence of weak forces. however they exist as soft solid  only when their molecules weight are high. 4.directional characteristics of covalent compound: covalent compound is

electronegativity scales and its advantages and numericals

electronegativity scales and its advantages and numericals 4.Sanderson's scale of electronegativity: this scale is based upon new quantity called stability ratio=E.D/E.Di  stability ratio of an atom is defined as ratio of average electron density (E.D)  around the nucleus and it's ideal hypothetical electron density (E.Di)  which the atom would have if it work on inert atom. stability ratio=E.D/E.Di A/c to sanderson's stability ratio of an atom measure it's electronegativity X(A) (sanderson) = E.D/E.Di Electronegativity on pauling scale: X(pauling) = 0.21(X(A)sanderson ratio) +0.77 5.Mulliken zaffee electronegativity scale: Zaffee and his coworker extended the Mulliken definition and suggested that electronegativity  of an atom is different in different environment some of these factor which affect electronegativity are 1.Oxidation state:  more is the oxidation state ,more is the attraction for electron,  hence more will be the electronegativity.