Chemical Bonding 4.1

Question 1

What is Octet Rule ?

Answer 1

tendency of atoms to gain a valence shell with a total of 8 electrons.

Question 2

Examples of Exceptions to Octet Rule

Answer 2

1) H2
2) He
3) BF3 ( B has 6 electrons)
4) SF6 (Sulphur has 12 electrons in its outer shell)
5) BeCl2 (Be has only 4 )

Question 3

Electro negativity definition

Answer 3

Measure of the attraction of an atom for a bonding pair of electrons.

Question 4

Electronegativity values and type of bonding

Answer 4

1) 0-0.4 = Non polar covalent
2) 0.5-1.7= Polar covalent
3) >1.7 = Ionic

Question 5

Ionic Bonding

Answer 5

Electrostatic attraction between oppositely charged ions.

1) Occurs between metals and non-metals.

Question 6

Properties of Ionic compounds

Answer 6

1) Don’t conduct electricity when solid, Only conduct electricity when molten or dissolved in water
2) Soluble in polar solvents

Question 7

effect of Ionic charge on MP

Answer 7

The greater the charge on the ion, the stronger the electrostatic attraction between the oppositely charged ions and higher the MP.

Question 8

effect of ionic radius

Answer 8

The greater the ionic radius, the weaker the electrostatic attraction between the oppositely charged and lower the MP