5. Chemical Bonding

Question 1

Compund

Answer 1

A substance made of two or more elements chemicals combined

Question 2

Octet rule

Answer 2

When bonding occurs, atoms tend to reach an electron arrangement with 8 electrons in the outermost energy level.

Question 3

What are the exceptions to the octet rule?

Answer 3

Transition metals

Hydrogen, Lithium & Beryllium (2)

Question 4

Ion

Answer 4

A charged atom or group of atoms.

Question 5

Cations

Answer 5

Positive ions

Question 6

Anions

Answer 6

Negative ions

Question 7

Ionic bond , eg

Answer 7

The force of attraction between oppositely charged ions in a compound. Ionic bonds are always formed by the complete transfer of electrons from one atom to another.
Eg NaCl

Question 8

What is the name of the three dimensional structure in which ions are encased?

Answer 8

Crystal lattice

Question 9

3 characteristics of transition metals

Answer 9

• variable valency
• coloured compounds
• catalysts
  VCC

Question 10

What elements included in the d block are not actually transition metals?

Answer 10

Scandium and Zinc

Question 11

Transition metal

Answer 11

One that forms at least one ion with a partially filled d sublevel.

Question 12

Molecule

Answer 12

A group of atoms joined together. It is the smallest particle of an element or compound that can exist independently.

Question 13

Valency

Answer 13

Valency of an element is defined as the no. of atoms of hydrogen or any other monovalent element with which each atom of the element combines.

Question 14

Sigma bond

Answer 14

A sigma bond is formed by the head on overlap of two orbitals.
(Single bonds) eg H2

Question 15

Pi bond

Answer 15

Pi bonds are formed by the sideways overlap of p orbitals.

Eg O2

Question 16

What type of bonds make up a single bond?

Answer 16

1 sigma bond

Question 17

What type of bonds make up a double bond?

Answer 17

1 sigma

1 pi bond

Question 18

What type of bonds make up triple bonds?

Answer 18

1 sigma

2 pi

Question 19

Which are stronger, sigma or pi bonds?

Answer 19

Sigma ; as there is more overlapping of orbitals in sigma bonds
Therefore O=O is not twice as strong as O-O.

Question 20

VSEPR

Answer 20

Valence Shell Electron Pair Repulsion

Electron pairs repel each other and arrange themselves in space so they can be as far apart as possible

Question 21

Angle of Triangular Planar

Answer 21

120

Question 22

Angle of linear

Answer 22

180

Question 23

Angle of pyramidal

Answer 23

107

Question 24

Angle of V shaped

Answer 24

104.5

Question 25

Angle of Tetrahedral

Answer 25

109.5

Question 26

Electronegativity

Answer 26

The relative attraction that an atom in a molecule has for the shared pair(s) of electrons in a covalent bond.

Question 27

Polar covalent bond

Answer 27

A bond in which there is unequal sharing of the pair(s) of electrons. This causes one end of the bond to be slightly negative and the other end slightly positive.

Question 28

Pure covalent

Answer 28

Equal sharing

Question 29

Exception to polar covalent bonds

Answer 29

Symmetrical molecules eg CO2 where the center of the negative charges coincide with that of the positive charges .

Question 30

Demonstrate polarity of water molecule

Answer 30

A charged plastic rod will always attract the water stream, whether negative or positive charged. Bc water molecules spin so that the neg/pod charge are attracted to rod.

Question 31

Predicting type of bonding based one electronegativity values

Answer 31

0- non polar (pure covalent) 0-0.4 negligible polar covalent 0.4-1.7 polar covalent 1.7+ ionic

Question 32

Intramolecular bonding

Answer 32

Bonding that takes place within the molecule ie it holds the atoms together. Eg Covalent, polar covalent

Question 33

Intermolecular forces

Answer 33

The forces of attraction that exist between molecules. Eg Van der Waals, dipole-dipole, hydrogen bonds.

Question 34

Van der Waals forces

Answer 34

Weak attractive forces between molecules resulting from the formation of temporary dipoles. They are the only forces of attraction between non-polar molecules Eg. H2

Question 35

Dipole-dipole forces

Answer 35

The forces of attraction between the negative pole of one polar molecule and the positive pole of another polar molecule. Eg HCl

Question 36

Hydrogen Bonds

Answer 36

Particular types of dipole-dipole attractions between molecules in which hydrogen atoms are bonded with nitrogen, oxygen or fluorine. NOF