Chemical Bonding I

Question 1

Chemical bonds

Answer 1

Electrostatic attractive forces between particles resulting in a lower energy arrangement

Question 2

Particles

Answer 2

Atoms, ions, or molecules

Question 3

Formation of chemical bond involves

Answer 3

Redistribution of electrons in the valence (outermost) shells of the atoms concerned

Question 4

Giant ionic structure

Answer 4

Ionic bond

Question 5

Giant metallic structure

Answer 5

Metallic bond

Question 6

Giant covalent structure

Answer 6

Covalent bond

Question 7

Simple covalent structure

Answer 7

Consists of covalent bond & intermolecular forces of attraction

Question 8

Hydrogen bonding exists…

Answer 8

Between water molecules

Question 9

Ionic bonds

Answer 9

Electrostatic forces of attraction (FOA) between oppositely charged ions

Question 10

Kernel

Answer 10

Nucleus + inner shell electrons

Question 11

Nature of ionic bonds

Answer 11

Non-directional -> each ion attracts ions of opposite charge in all directions

Are strong bonds

Question 12

Covalent bond

Answer 12

Electrostatic FOA between positively charged nuclei of each atom & their shared pair of electrons (negatively charged)

Question 13

Bond pair of electrons

Answer 13

Valence electrons involved in the formation of the covalent bond

Question 14

Lone pair of electrons

Answer 14

Valence electrons not involved in bonding

Question 15

“Normal” CB

Answer 15

Both orbitals are singly occupied with an electron of opposite spin to each other

Question 16

Dative CB

Answer 16

1 orbital filled with a pair of electrons while the other orbital is an empty orbital

Question 17

Localised

Answer 17

Bonding electron pair is confined within the valence orbitals of the two atoms

Question 18

Nature of covalent bonds

Answer 18

Strong (each pair of shared electrons is attracted by both the positively charged nuclei involved in the bonding)
Directional

Question 19

Bond length

Answer 19

Inter-nuclear distance between two atoms involved in the bonding

The optimum bonding distance between ^

Maximum overlap of atomic orbitals containing shared electron pair

Forms molecular orbital

Question 20

Sigma bond

Answer 20

Formed by head-on (or end-on) overlap

Question 21

Pi bond

Answer 21

Formed when there’s sideways overlap of atomic orbital of p orbitals only

Question 22

Bond energy

Answer 22

Energy, in kJ mol−1, required to break 1 mole of covalent bonds between 2 atoms in the gaseous state, or a particular type of bond in a gaseous poly atomic molecule to give gaseous atoms

Question 23

Uses of bond energy

Answer 23

Compare strengths & reactivities
Estimate enthalte (heat) changes

Question 24

Bond order

Answer 24

Number of covalent bonds formed between 2 atoms involved in the bonding

Question 25

Electronegativity for CB A-B

Answer 25

Measure of the ability of atoms A or B to attract the bonding electrons

Question 26

Factors contributing to high degree of covalency in ionic compounds

Answer 26

High cation charge Small size of cation Large size of anion

Question 27

Bond angles

Answer 27

180 120 109 90 & 120 90

Question 28

Factors affecting bond angles

Answer 28

Number of lone pairs of electrons Electronegativity of central atom Size of atoms attached