2.2.2 Bonding

Question 1

what is ionic bonding

Answer 1

Transfer of electrons resulting in a repeating pattern of oppositely charge ions.

Question 2

what is the usual melting point of a ionically bonded substance and why

Answer 2

high due to strong electrostatic attraction

Question 3

ionic bonding electrical conductivity

Answer 3

when molten/dissolved

Question 4

what is covalent bonding

Answer 4

overlap of atomic orbitals to share a pair of electrons

Question 5

do covalent bonded substances conduct electricity

Answer 5

no

Question 6

octet rule

Answer 6

unpaired electrons pair up so their is always 8 electrons in outershell

Question 7

why is the octet rule not always followed (2 point)

Answer 7

may not be enough electrons to react or more than 4 electrons may pair up

Question 8

What are the 2 elements that can form less than 4 bonds/have less than 8 outer electrons. and why

Answer 8

Beryllium and boron. as they dont have enough electrons and will pair what’s available.

Question 9

Example of a covalent bond with more than 8 outer electrons

Answer 9

SF6

Question 10

What is a dative bond.

Answer 10

Covalent bond where both electrons come from the same atom.

Question 11

How do dative bonds form

Answer 11

One atom that has a non-bonding pair of electrons and another atom that can accept 2 electrons.

Question 12

What 2 things determine the 3-d structure of a molecule

Answer 12

Number of bonding pairs, number of non bonding pairs.

Question 13

What is VSEPR

Answer 13

Valence shell electron pair repulsion theory

Question 14

Angle and name of a molecule with 2 bonds

Answer 14

180° linear

Question 15

Angle and name of a molecule with 3 bonds

Answer 15

120° trigonal planar

Question 16

Angle and name of a molecule with 4 bonds

Answer 16

109.5° Tetrahedral

Question 17

Angle and name of a molecule with 6 bonds

Answer 17

90° octahedral

Question 18

How many ° are taken per lone pair of electrons

Answer 18

2.5°

Question 19

Order of repulsion (electron pair types)

Answer 19

Bonded-bonded < Bonded-Lone < Lone-Lone.

Question 20

Angle and name of a molecule with 3 bonded pairs and 1 lone pair

Answer 20

107° pyramidal

Question 21

Angle and name of a molecule with 2 bonded pairs and 2 lone pairs of electrons

Answer 21

104.5° non-linear

Question 22

What is electronegativity

Answer 22

The ability to attract the bonding electron pair

Question 23

Top 3 electronegative elements in order

Answer 23

Nitrogen, Oxygen and fluorine. (NOF)

Question 24

2 factors that affect electronegativity and how,

Answer 24

1 atomic radius - radius increases-> distance from nucleus increases-> less attraction -> lower electronegativity
2 number of unshielded protons - more protons -> more attraction -> higher electronegativity

Question 25

What is the effect of full energy levels on electronegativity

Answer 25

Decreases

Question 26

What is a polar bond

Answer 26

An uneven distribution of electron density

Question 27

What causes polar bonds

Answer 27

When two have different electronegativity

Question 28

What are non-polar bonds

Answer 28

When electron density is shared evenly

Question 29

What causes non-polar bonds

Answer 29

When both atoms have identical electronegativity

Question 30

What symbol is used to show positive polar bond partial charge

Answer 30

δ+

Question 31

What symbol is used to show negative polar bond partial charge

Answer 31

δ-

Question 32

What is a Polar Molecule

Answer 32

A molecule with a large charge on one side that is not cancelled out. Generally unsymmetrical

Question 33

Are polar bonds covalent or ionic

Answer 33

Either

Question 34

What is a dipole

Answer 34

A molecule with 2 poles

Question 35

What are intermolecular forces

Answer 35

Forces that hold together molecules in a substance

Question 36

Are bonds broken when intermolecular forces are overcome

Answer 36

No (boiling water)

Question 37

What are London forces

Answer 37

Induced dipole dipole, when at any instant the electron of an atom find themselves at one end of atom a temporary charge is created. Another molecule close enough can have an induced charge from this dipole interaction.

Question 38

What increases London force strength

Answer 38

More electrons in molecule - larger induced dipole - stronger forces - more energy required to overcome.

Question 39

What are permanent dipole-dipole interactions

Answer 39

They act between permanent dipoles in different molecules.

Question 40

What are hydrogen bonds

Answer 40

A special case of permanent dipole dipole interactions that are stronger than London forces and permanent dipole dipole forces.

Question 41

what is required for a hydrogen bond to form

Answer 41

A hydrogen bonded to a electronegative atom (NOF) with a lone pair of electrons.

Question 42

waters 3 anomalous properties

Answer 42

1. Hydrogen bonds push molecules further apart in open lattice structure ( when frozen) 2. Molecules further apart in solid 3. Solid ice is less dense than liquid water and floats.

Question 43

do simple molecular substances have a high or low melting/boiling point.

Answer 43

low due to weak intermolecular forces that can be easily overcome.

Question 44

what solvent will dissolve non-polar simple molecules

Answer 44

non-polar solvents

Question 45

what solvent will dissolve polar simple molecules

Answer 45

polar solvents

Question 46

Do simple molecular substances conduct electricity

Answer 46

no as there are no charged particles that are able to move.