week 2

Question 1

netrophiles

Answer 1

atom with lone pair of electrons or a pi bond

attract to electrophiles

Question 2

elctrophiles

Answer 2

either vacant orbitals or polarized bond

attract e- to them

Question 3

What is aniline?

Answer 3

Aniline is an organic compound consisting of a phenol group attached to an amino group

10^6 less basic

Question 4

What is an aryl group?

Answer 4

A functional group derived from a simple aromatic ting compound where one hydrogen atom is removed from the ring

Question 5

What is benzene?

Answer 5

An organic chemical compound the chemical formula C6H6. Because of the cyclic continuous pi bond between the carbon atoms, benzene is classed as an aromatic hydrocarbon

Question 6

What are electrophiles?

Answer 6

A positive or neutral species having vacant orbitals that are attracted to an electron rich centre

Question 7

What is a covalent bond?

Answer 7

A chemical bond that involves the sharing of electron pairs between atoms

Question 8

benzene elctrons

Answer 8

The π electrons in benzene are equally spread over the carbon atoms in the molecule.
These π electrons are delocalized over all six of the atoms in the ring meaning they are not localized in specific double bonds between two precise carbon atoms.

Question 9

What is hybridisation?

Answer 9

When atomic orbitals combine to form a new atomic orbital

Question 10

What are nucleophiles?

Answer 10

A chemical species that donates an electron pair to an electrophile to form a chemical bond in relation to a reaction

Question 11

What is the ortho position?

Answer 11

When the functional group is on the carbon adjacent to another carbon with a functional group

Question 12

What is a phenol?

Answer 12

A class of chemical compounds consisting of a -OH group bonded directly to an aromatic hydrocarbon group

Question 13

What is resonance theory?

Answer 13

Theory by which the actual normal state of a molecule is represented not by a single valence-bond structure but by a combination of several alternative distinct structures.

Question 14

What does the reaction mechanism describe?

Answer 14

The formation and breakage of bonds

Question 15

What makes a carbocation primary, secondary or tertiary?

Answer 15

Depends on the number of carbons bonded to the carbon bearing the positive charge

Question 16

Are carbocations Lewis acids or Lewis bases?

Answer 16

Lewis acids - they accept electron pairs

Question 17

True or False: Benzene is a planar molecule

Answer 17

True

Question 18

What special characteristic associated with planar ring systems allows for aromacity?

Answer 18

De-localised p-orbital system

Question 19

What are the criteria for Huckel’s rule?

Answer 19

to be aromatic A ring must:

Have one 2p orbital on each of its atoms
Be planar, or almost planar, so that there is overlap between all 2p orbitals
Have 2, 6, 10, 14, 18 and so on π electrons in the cyclic arrangement of 2p orbitals

Question 20

Why is phenol more acidic than aliphatic alcohols?

Answer 20

Because the phenoxide ion is delocalised over the whole aromatic ring so it is very easy to remove the H ion

Question 21

How do you name an amine?

Answer 21

Replace the suffix -e of the parent alkane with -amine

Question 22

Are amines acidic or basic?

Answer 22

Basic

Question 23

All acceptable electron redistrobutions (bond break/make) must:

Answer 23

1. Have the same number of valence electrons
2. Obey the rules of covalent bonding
3. only in distribution of valence electrons
   Have the same number of 4. paired and unpaired electrons
4. Have a charge balance following redistribution

Question 24

What determines whether an alcohol is primary, secondary or tertiary?

Answer 24

The number of carbons attached to the carbon attached to the -OH group.
1 carbon = primary
2 carbons = secondary
3 carbons = tertiary

Question 25

How is an alcohol converted into an alkyl halide?

Answer 25

Substitution of halogen for -OH

Question 26

What are the most common reagents for the conversions of alcohol to alkyl halide?

Answer 26

The halogen acids (i.e. HCl, HF etc.) and Thionyl chloride (SOCl2)

Question 27

Which type of alcohol (primary, secondary, tertiary) is very reactive with the halogen acids?

Answer 27

Tertiary

Question 28

What do primary alcohols oxidise to?

Answer 28

Aldehydes or carboxylic acids

Question 29

What do secondary alcohols oxidise to?

Answer 29

Ketones

Question 30

What do tertiary alcohols oxidise to?

Answer 30

They don’t, they are resistant to oxidation

Question 31

Why is benzene more stable than the triene model suggests?

Answer 31

The resonance energy makes benzene stronger than expected

Question 32

For a phenol, which positions on the molecule are negatively charged?

Answer 32

The -OH group pushes electron density onto the ortho- and para- positions

Question 33

Why are aromatic amines weaker bases than aliphatic ones?

Answer 33

The resonance interactions spreads the electron density therefore it is less able to pull a H ion away from another molecule