Covalent bonding - HL

Question 1

What do the delocalised electrons do in a resonance structure ?

Answer 1

The delocalised electrons are spread evenly across the bonding positions where the double bond can be found

Question 2

How would you know if someone would display resonance ?

Answer 2

If there is more than one place for a double or triple bond , then the molecules can display resonance

Question 3

What physical evidence suppprts the resonance structure of benzene

Answer 3

All carbon-carbon bonds are of equal length with equal binding angle of 120

Question 4

Define bond energy

Answer 4

The bond energy is required to break one mole of a particular covalent bond in the gaseous state

Question 5

Triple bonds are the

Answer 5

shortest and strongest
due to large lecturing density

Question 6

Single covalent bonds are

Answer 6

longest and weakest

Question 7

2 ED 0 LP

Answer 7

linear

Question 8

3ED 0LP

Answer 8

Trigonal Planar

Question 9

lone pairs reduce

Answer 9

bond angle

Question 10

4 ED 0LP

Answer 10

Tetrahedral

Question 11

3BP 1 LP

Answer 11

trigonal pyramidal

Question 12

2 BP 2LP

Answer 12

bent

Question 13

2BP 1LP

Answer 13

Bent

Question 14

what bond angle is linear

Answer 14

180

Question 15

what bond angle is trigonal planar

Answer 15

120

Question 16

what bond angle is tetrahedral

Answer 16

109.5

Question 17

Shape of 5BP 0LP

Answer 17

Trigonal Bipyramidal

Question 18

Shape of 4BP 1LP

Answer 18

See-saw

Question 19

Shape of 3BP 2LP

Answer 19

T-shaped

Question 20

Shape of 2BP 3LP

Answer 20

Linear

Question 21

Shape of 6BP 0LP

Answer 21

Octahedral

Question 22

Shape of 5BP 1LP

Answer 22

Square Pyramidal

Question 23

Shape of 4BP 2 LP

Answer 23

Square Planar

Question 24

Shape of 3BP 3 LP

Answer 24

T-shaped

Question 25

Shape of 2BP 4LP

Answer 25

bent

Question 26

what is a dipole

Answer 26

measure of how polar a bond is

Question 27

When a diatonic molecule e.g cl2 the electronegativity is shrared equally therefore the covalent bond is

Answer 27

non-polar

Question 28

When two atoms in a covalent bond have different electronegativities what is the covalent bond

Answer 28

polar

Question 29

the bigger the difference in electro negativity the

Answer 29

higher the polarity of the covalent bond

Question 30

the dipole arrow points to the

Answer 30

partially negative charged end

Question 31

What needs to be taken into consideration when a molecule has more than two atoms when deciding the polarity

Answer 31

• The polarity of each bond within the molecule • How the bonds are arranged in the molecule

Question 32

when the pull of the atoms are not equal and opposite there is a net pull so

Answer 32

the molecule is polar

Question 33

what is the formula of silicon oxide

Answer 33

Si02

Question 34

Why do giant covalent lattice have high melting and boiling points

Answer 34

large number of covalent bonds , a lot of energy is required to break the lattice

Question 35

6 examples of giant covalent structures

Answer 35

diamond , graphite , graphene , buckminsterfullerene , silicon , silicon dioxide

Question 36

what are the three type of intermolecular forces

Answer 36

London dispersion forces Dipole-dipole attraction hydrogen bonding

Question 37

London forces are

Answer 37

present between all atoms and molecules

Question 38

The strength of the london dispersion forces depends on two factors

Answer 38

number of electrons in the molecule surface area of the molecules

Question 39

The greater the number of electrons in the molecule the

Answer 39

stronger the dispersion forces and melting/boiling points are stronger

Question 40

What is the strongest intermolecular force

Answer 40

Hydrogen bonding

Question 41

For hydrogen bonding to take place it needs a species which has

Answer 41

(F,O,N) with an available lone pair of electrons

Question 42

How to work out RF value

Answer 42

distance travelled by component/ distance travelled by solvent

Question 43

What is the equation for formal charge

Answer 43

FC = (number of valence electrons) - 1/2(number of bonding electrons) - (number of non-bonding electrons) FC = V - 1/2B-N

Question 44

the lewis formal which is preferred is the FC

Answer 44

closest to 0

Question 45

How is a sigma bond formed

Answer 45

the head on overlap (axial or end to end) of atomic orbitals (s-s) (s-p) (p-p)

Question 46

How is a pi bond formed

Answer 46

by sideways overlap of atomic orbitals

Question 47

how many sigma and pi bonds in a single covalent

Answer 47

1 sigma 0 pi

Question 48

how many sigma and pi bonds in a double covalent bond

Answer 48

1 sigma 1 pi

Question 49

how many sigma and pi bonds in a triple covalent bond

Answer 49

1 sigma 2 pi