Organic chemistry - 1

Question 1

what is mass spectrometry used for?

Answer 1

used to find accurate formula mass and structural features of an organic compound

Question 2

during mass spectrometry, what is the molecule broken up into?

Answer 2

smaller positively charged ion fragments

Question 3

what accelerates the positive ion fragments?

Answer 3

accelerated by high voltage electric field into magnetic field

Question 4

how are compounds identified in mass spectrometry?

Answer 4

identified by relative molecular masses of parent ion and ion fragments

Question 5

what happens when atomic orbitals overlap?

Answer 5

molecular orbitals

Question 6

what makes up a σ (sigma) bond?

Answer 6

two 1s orbitals

Question 7

what is more stable, the 1s atomic orbital or the σ (sigma) molecular orbital?

Answer 7

σ (sigma) molecular orbital

Question 8

what is a sigma bond?

Answer 8

covalent bonds formed between atoms when end-on overlap of orbitals occur

Question 9

what has a lower energy - atomic or molecular orbital?

Answer 9

molecular orbital

Question 10

what allows free rotation in molecules with σ (sigma) bonds?

Answer 10

sigma bonds lie along line joining both atoms

Question 11

what does the shape of the molecular orbital govern?

Answer 11

governs the type of intermolecular bonding thats involved

Question 12

what are the three types of intermolecular bonding?

Answer 12

• non-polar covalent
• polar covalent
• ionic

Question 13

if a molecular orbital is symmetrical around mid-point where bonding electrons are, what type of intermolecular bonding are involved?

Answer 13

non-polar covalent

Question 14

if there are polar covalent bonds what shape will the molecular orbital be?

Answer 14

bonding molecular orbital will be asymmetrical

Question 15

what shape will be present when ionic bonds occur?

Answer 15

extreme asymmetry and bonding molecular orbital is almost entirely around one atom

Question 16

what is hybridisation?

Answer 16

process of mixing atomic orbital within an atom

Question 17

what is generated through hybridisation?

Answer 17

new set of atomic orbitals called hybrid orbitals

Question 18

what makes up an sp3 orbital?

Answer 18

one 2s + three 2p atomic orbitals

Question 19

what shape is an sp3 orbital?

Answer 19

tetrahedral

Question 20

what can sp3 orbitals be described as?

Answer 20

degenerate orbitals and half filled

Question 21

what is bond fission?

Answer 21

the process of breaking bonds

Question 22

what is homolytic fission?

Answer 22

two species of the same charge are formed

Question 23

what is formed during homolytic fission?

Answer 23

free radical - each fragment has unpaired electron

Question 24

what is a downside to free radical substitution reactions?

Answer 24

many complex mixture of products

Question 25

when does heterolytic fission occur?

Answer 25

normally occurs when polar covalent bonds are broken

Question 26

In heterolytic bond fission, which atom of the bond keeps both bonding electrons?

Answer 26

the more electronegative atom of the bond - ends up as negatively charged

Question 27

which type of fission is better for synthesis of organic compounds?

Answer 27

heterolytic since less products are produced

Question 28

what is a nucleophile?

Answer 28

negatively charged ion or neutral molecule that are electron rich

Question 29

what is the term used to describe an electron-pair donor?

Answer 29

nucleophile

Question 30

what will a nucleophile attack?

Answer 30

attack species with a positive charge

Question 31

what are some common examples of nucleophiles?

Answer 31

Br-, OH-, NH3

Question 32

what is an electrophile?

Answer 32

positively charged ions or neutral molecules that lack electrons

Question 33

what is the term used to describe an electron-pair acceptor?

Answer 33

electrophile

Question 34

what will an electrophile attack?

Answer 34

attack species with a negative charge

Question 35

what are some common examples of electrophiles?

Answer 35

H+, NO2+, SO3