Chemical Bonding Solved Exercise

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Solved Text Book Exercise from chapter 6 chemical bonding chemistry book 1 for FSC pre engineering and pre medical for Board of Intermediate and Secondary education. Also For Entry Test Preparation for UET, NUST, PIEAS, GIKI, AIR, FAST, WAH University, UHS, other engineering Universities and Medical Colleges.

1. An ionic compound A⁺B^- is most likely to be formed when

2. The number of bonds in nitrogen molecule is

3. Which of the following statements is not correct regarding bonding molecular orbitals?

4. Which of the following molecules has zero dipole moment?

5. Which of the hydrogen halides has the highest percentage of ionic character?

6. Which of the following species has unpaired electrons antibonding molecular orbitals?

1. The tendency of atoms to attain maximum of ________ electrons in the valence shell is called completion of octect.
2. The geometrical shape of SiCl4 and PCl3 can be explained on the has of ________ and ________ hybridizations.
3. The VSEPR theory stands for ________.
4. For N₂ molecule, the energy of (2p)_x orbital is ________ than(2p_y) orbital.
5. The paramagnetic property of 0₂ is well explained on the basis on M.O theory in terms of the presence of _________ electrons in two M.O orbitals.
6. The bond order of N₂ is ________ while that of Ne₂ is ________.
7. The values of dipole moment for CS₂ is ________ while for SO₂ is ________.

1. The core of an atom is the atom minus its valence shell.
2. The molecules of nitrogen (NN) and acetylene (HCCH) are not iso-electronic.
3. There are four coordinate covalent bonds in ion.
4. Abond is stronger thanbond and the electrons ofbond are more diffused than bond.
5. The bond energy of heteroatomic diatomic molecules increases with the decrease in the electro negativities of the bonded atoms.
6. With increases in bond order, bond length decreases and bond strength increases.
7. The first ionization energies of the elements rise steadily with increasing atomic number from top to bottom is a group.
8. A double bond is stronger than a single bond and a triple bond is weaker than a double bond.
9. The bonds formed between the elements having electro negativity difference more than 1.7 are said to be covalent in nature.
10. The repulsive force between then two bonding pairs is less than that between the two lone pairs.
11. The number of covalent bonds an atom can form is related to the number of unpaired electrons it has.
12. The rules which govern the filling of electrons into the atomic orbitals also govern the filling of electrons into the molecular orbitals.

1. The elements with low I.E are metals
2. The elements with high I.E are non-metals
3. The elements with intermediate I.E values are metalloids.

1. Atomic radius or atomic size
2. Nuclear charge (Proton number) of atom
3. Shielding effect of inner electrons
4. Nature of orbital

1. Atomic radius
2. Nuclear charge
3. Shielding effect of inner electrons
4. Nature of orbital

1. E.A in a Group:

2. E.A in a Period:

1. Bond distance is the compromise distance between two atoms.
2. The distinction between a coordinate covalent bond and a covalent bond vanishes after bond formation in, H₃O⁺ and.
3. The bond angles of H₂O and NH₃ are not 109.5^o like that of CH₄. Although, 0-and N-atoms are sp³hybridized.
4. are more diffused than.
5. The abnormality of bond length and bond strength in HI is less prominent than that of HCl.
6. Solid sodium chloride does not conduct electricity, but when electric current is passed through molten sodium chloride or its aqueous solution, Electrolysis takes place.
7. The melting points, boiling points, heat of vaporization and heats of sublimations of electrovalent compounds are higher as compared with those of covalent compounds.

1. When two atoms come close to make a bond, then their attraction increases and P.E decreases. At a certain distance atomic attraction is maximum and energy is minimum. It is compromise distance between two atoms. Here bond formation takes place. It atoms come further closer, then nuclear repulsions takes place and energy of system increases. Here bond formation does not occur. Hence bond distance is the compromise distance between two atoms.
2. In a covalent bond two atoms provide shared pair of electrons. In a coordinate covalent bonds and one coordinate bond then there is no difference between their bond length and bond energy. E.g. inion all four bonds are taken equally. It is the reason that distinction between covalent and coordinate covalent bond vanishes after their formation.
3. In NH₃ and H₂O there is SP³ hybridization like CH₄. Four SP³ hybrid orbitals are formed. The angle between SP³ orbitals should be 109.5^o. But we know that NH₃ has one lone pair and H₂O has two lone pairs of electrons. There is repulsion between lone pairs and bonding pairs of electrons. Due to lone pair-bond pair repulsion the bond angles in NH₃ and H₂O are not 109.5^o like CH₄ which has no lone pair of electrons.
4. Sigma bond is formed by head to head (liner) overlap of two partially filled orbitals. Here electron density is symmetrically spread around the bond axis. The Pi-bond formed by parallel overlap of two partially filled P-orbitals. Here electron density is spread above and below the bond axis. It is the reason thatare more diffused than.
5. Chlorine has smaller size and higher electro negativity than Iodine. Thus HCl has more polarity than HI. Due to this reason abnormality of bond length and bond strength in HI is less prominent than that of HCl.
6. In solid sodium chloride, the Na⁺ and Cl^- ions have strong electrostatic attractions. Thus they are tightly held and occupy fixed positions. But in molten or solution form, ions become free and move towards opposite electrodes. It is the reason that sold NaCl does not conduct electricity but in molten or solution form NaCl conducts electricity.