Chemical bonding 2 Flashcards
Although geometries of NS3 and H2O molecules are distorted tetrahedral bond angle in water is less than that of ammonia discuss
NH3 molecule has one lone pair with H2 has two lone pairs of Electrons due to the presence of lone pairs the geometry of NS3 and H2O are distorted due to the presence of a stronger lp-bp Repulsion than bp-bp repulsion, The bond angle in NH3 is reduced from normal tetrahedral bond angle 109.5 degrees to 107 degrees. In case of H2O, two lp of electrons force O-H bonds more closely than N-H bonds in NH3. So the Bond Angle decreases to a larger extent i.e, to 104.5 degrees.
Arrange the bonds in order of increasing ionic character in the molecules: LiF, K2O, N2, So2, ClF3
N2<SO2<ClF3<K2O<LiF
apart from tetrahedral geometry another possible geometry for CH4 is square planar with the 4 H atoms at the corner of the square and the C item at its center explain why CH4 is not a square planar.
In square planar geometry the bond angle will be 90 degrees which is less than bond angle in tetrahedral geometry which is 109.5 degrees. Therefore repulsive forces between electron pairs will be more in square planar geometry and it will be less stable in comparison to tetrahedral geometry.
Write the significance of a plus and a - shown in representing orbitals
The plus and - corresponds to sine of electron wave . The crest of a wave are usually given by a positive sign and troughs of a wave are given by and the negative sign.
Is hydrogen bond weaker or stronger than van der Waals force?
Hydrogen bond is stronger than vanderwaal’s force of attraction
covalent bonds are directional bonds while ionic bonds are non directional.
In a covalent bond, the overlapping between half-filled atomic orbitals which have definite directions take place, shared electron pairs are localized between two atoms. Thus, covalent bond is known as directional bond. In ionic compounds each ion has its influence in all direction hence it is surrounded by a number of oppositely charged ions with no definite direction.
Why Ethyne molecule in linear
it is because each carbon atom in ethyne is sp hybridization
distinguish between antibonding orbitals and nonbonding orbitals
antibonding orbitals have higher energies than the highest atomic orbital from which they are formed. on the other hand, nonbonding orbitals have the same energy as the atomic orbitals from which they are formed.
why are noble gases monoatomic
-cuz of their high stability which does not allow them to form bonds with other atoms and stay free.
although chlorine has the same electronegativity as nitrogen, it does not form hydrogen bonding. Explain.
- The size of N is smaller than that of Cl. As a result, N atom can cause greater polarization of N-H bonds than the Cl atom in Cl-H bonds.
ice or water which has lower density
-ice
due to its intermolecular hydrogen bonding and cage like structure.
presence of lone pair distorts the molecule explain with an example.
The bonded pair of Electrons is attracted by the nuclei of both the bonding atoms. The lone pairs are localized on the central atom, Each bonded pet is shared between two atoms. As a result, the lone pair electrons in a molecule occupy more angular space as compared to the bonding pairs of electron. This results in greater repulsion between the lone pairs of Electrons as compared to the lone pair bond pair repulsion and bond pair bond pair repulsion. These repulsion effect results in deviation from idealized shape and alterations in bond angle in molecules.
For example in SO2 molecule, Theoretically the shape should have been triangular planar but actually it is found to be bent or V shaped. The reason being the lone pair bond pair repulsion is much more as compared to the bond pair bond pair repulsion. Show the angle is reduced to 119.5 degrees from 120 degrees
