Bonding

Question 1

covalent bonding

Answer 1

Has a pair of Electrons with opposed spin shared between two atoms with each atom giving one election

Question 2

Ionic bonding

Answer 2

Bond formed by the electrical attraction between positive and negative ions ( Cation and anions)

Question 3

coordinate bonding

Answer 3

Covalent bond in which both shared electrons come from one of the atoms

Question 4

Attractive and repulsive forces

Answer 4

All bonding results from electrical attractions and repulsions between the protons in the nucleus and the electrons which with attractions are weighing repulsions

Question 5

Attractive and repulsive forces and covalent bonds

Answer 5

Electrons in the pair between atoms repel one another but this is overcome by their attractions to BOTH nuclei.
If atoms get too close together the nuclei and their inner electrons will repel those of the other atom, so the bond has a certain length
Electrons spin must be opposite for the bonds to fall

Question 6

Attractive and repulsive forces and ionic bonds

Answer 6

Cations and anions are arranged so that each cation is surrounded by several anions and vice versa to maximise attraction and minimise repulsion
Repulsions from inner electrons and nuclei prevent the ions from getting too close together

Question 7

Electronegativity

Answer 7

Measure of the electron attracting power of an atom in a covalent bond

Question 8

polar bond

Answer 8

Has one end of the bond with a slightly positive charge than the other end with a slightly negative charge
Eg. Dipole
Molecule is neutral overall

Question 9

Intermolecular bonding

Answer 9

The weak bonding holding the molecules together
Eg. In liquids
Governs the physical properties of the substance

Question 10

intramolecular bonding

Answer 10

Strong bonding between the atoms in the molecule and governs its chemistry

Question 11

Van der waals forces

Answer 11

Includes all types of intermolecular forces weather dipole or induced dipole

Question 12

Three types of intermolecular forces

Answer 12

dipole-dipole forces
Induced dipole induced dipole forces
Hydrogen bonds

Question 13

Dipole to dipole forces

Answer 13

Polar molecules have dipoles- one end is slightly positive and the other sightly negative due to differences in electronegativities between atoms
Attraction between negative and positive regions
Dipole forces- permanent dipole

Question 14

Induced dipole to induced dipole forces

Answer 14

Forms when the electron orbitals around a molecule are influenced by another charged particle

Question 15

Hydrogen bonds

Answer 15

Interaction between H atom bonded to small, very electronegative elements which have lone pairs- F,O,N
They are highly electronegative and the H atom is so small, plus charge in bonded hydrogen atom is spread over small volume and it has high charge density
Highly polarising

Question 16

Effect of hydrogen bonding in boiling and melting temperatures

Answer 16

hydrogen bonds are stronger than van der Waals forces- Molecules that form hydrogen bonds have a higher BP

Question 17

Effect of hydrogen bonding in solubility

Answer 17

Most significant intermolecular forces between water molecules are hydrogen bonds.
Covalent compounds that can replace these bonds by forming new hydrogen bonds with water will dissolve

Question 18

Valence shall electron pair repulsion theory (VSEPR)

Answer 18

Any loan pays present around central Atom provide additional repulsive forces, which change the bond angle and shape of molecule
Eg For every lone pair present, bond angle between covet and bond is reduced by 2.5

Question 19

Shape of molecules and ions

Answer 19

1. Find number of Electrons in outer shell
2. Add one electron for each bond being formed
3. (add 1 electron for 1-, remove one electron for 1+)
4. Divide total number of Electrons by two to find number of electron pairs
5. Compare number of electron pairs with number of bonds to find number of bonding pairs and lone pairs

Question 20

Metallic bonding

Answer 20

force of attraction between free moving delocalised electron and a positive metal

Question 21

Group 4 hydrides, group 5 and 6

Answer 21

The boiling temperatures increase as you go down the group because the molecules are getting larger with more electrons, and so the van der Waals forces become stronger

Question 22

value for NH3 and H20

Answer 22

Much higher than other hydrides in their groups because extra energy is needed to break the hydrogen bonds between molecules

Question 23

Linear shape

Answer 23

2 bonding pairs
0 number of lone pairs
Eg. Co2, BeCl2
Bond angle- 180

Question 24

trigonal planar

Answer 24

3 no. Of bonding pairs
No lone pairs
BF3 AICl3, 120

Question 25

Tetrahedral

Answer 25

Four bonding pairs
No lone pairs
CH4 NH4+, 109.5

Question 26

Bent or V shaped

Answer 26

2 bonding pairs
2 lone pairs
Eg. H2O F2O, 104.5
Loan pay - loan pay propulsion forces the bonding pays even closer and reduces angle between them to 104.5

Question 27

Trigonal pyramidal

Answer 27

3 bonding pairs
1 lone pairs
Eg. NH3 H3O+, 107
There is more potion between a lone pair and a bonding pair than between two bonding pairs and forces bonding pairs together slightly reducing bond angle

Question 28

Octahedral

Answer 28

6 bonding pairs
0 lone pairs
Eg. SF6, 90

Question 29

Triagonal bipyramidal

Answer 29

5 bonding pairs
0 Lone pairs
Eg. PCl5, 120, 90
Propulsion between bonding pairs means that three of the atoms are in the plane at 120 and other two atoms are at right angles

Question 30

electronegativity in periodic table

Answer 30

Increases a longer. As atomic radius decreases
Decreases down a group as shielding increases
Fluorine is the most electronegative
The higher the electronegativity, the better the element can attract bonding electrons

Question 31

non polar covalent bonds

Answer 31

If electronegatively difference between two atoms is less than 0.4

Question 32

polar covalent bonds

Answer 32

If difference is between0.4 and 1.9

Question 33

More ionic bond

Answer 33

If the difference is about 2.0 or more