Organic Compounds

Question 1

What are the 4 chloroalkanes?

Answer 1

1) Chloromethane
2) Dichloromethane
3) Trichloromethane
4) Tetrachloromethane

Question 2

What were chloroalkanes originally used for?

Answer 2

Anaesthetic (chloroform)

Question 3

What are modern uses of chloroalkanes?

Answer 3

Sovents: removing oil and grease and dry cleaning

Question 4

What are the properties of chloroalkanes?

Answer 4

Non-polar
Dissolve in non-polar solvents (cyclohexane)
Low boiling points

Question 5

What is a functional group?

Answer 5

Functional group is an atom or a group of atoms which are responsible for the characteristics of a series of organic compounds

Question 6

What is the functional group of alcohols?

Answer 6

OH

Question 7

What shape are alcohols?

Answer 7

Tetrahedral

Question 8

What is a primary alcohol?

Answer 8

One carbon attached to the carbon attached to the OH.

Question 9

What is a secondary alcohol?

Answer 9

2 carbons attached to the carbon attached to the OH.

Question 10

What is a tertiary alcohol?

Answer 10

3 carbons attached to the carbon attached to the OH.

Question 11

What letter is used to represent an alkyl group?

Answer 11

R

Question 12

What are uses of ethanol?

Answer 12

Perfume, lotion and dyes

Question 13

Whats the functional group of aldehydes and ketones?

Answer 13

C=0 (CHO)

Question 14

What the structural difference between aldehydes and ketones?

Answer 14

Aldehydes:C=0 at end of chain
Ketones:C=0 middle of chain

Question 15

What are the functions of some aldehydes and ketones?

Answer 15

Propanone: solvent in paints, varnishes, nail polish

Methanal: preserving/embalming, polymer adhesives

Question 16

What are the four carboxylic acids?

Answer 16

1) Methanoic
2) Ethanoic
3) Propanoic
4) Butanoic

Question 17

What are some properties of carboxylic acids?

Answer 17

Colourless with sharp distinctive smells
Higher boiling points than alcohols of same mass
4 carbons are soluble
>4 carbons are less polar and less soluble

Question 18

What are some uses/occurrences of carboxylic acids?

Answer 18

1) Methanoic acid in ant stings
2) Ethanoic acid is vinegar. It can also be used to manufacture cellulose acetate for varnish and photographic film.
3) propanoic acid- salts for food preservation

Question 19

What is the functional group for carboxylic acids?

Answer 19

COOH

Question 20

What is the functional group for carboxylic acids?

Answer 20

COOH

Question 21

What is the boiling point of ethanal?

Answer 21

21C

Question 22

Common uses for esters?

Answer 22

Fragrances, essential oils and pheromones.

Question 23

What is the functional group of esters?

Answer 23

COO

Question 24

What is the general formula for esters?

Answer 24

RCOOR’

Question 25

How are esters made?

Answer 25

Condensing acids with alcohols

Question 26

What is a substitution reaction?

Answer 26

A chemical reaction in which an atom or a group of atoms in a molecule are replaced by another atom or group of atoms.

Question 27

What is a free radical?

Answer 27

Any species with a free, unpaired electron.

Question 28

What is a chain reaction?

Answer 28

Reaction that continues on and on because a product from one step of the reaction is the reactant for another step.

Question 29

What do you get when you add chlorine to methane?

Answer 29

Chloromethane and hydrogen chloride.

Question 30

Features of free radical reactions?

Answer 30

Often explosive and difficult to control due to extremely reactive nature of radicals.

Question 31

What are the 3 steps in a substitution reaction?

Answer 31

Initiation, propagation and termination.

Question 32

What happens in initiation?

Answer 32

Diatomic molecule chlorine undergoes homolysis when exposed to UV light.

Question 33

What happens in propagation?

Answer 33

Chlorine radical attaches to the methane to from hydrogen chloride and a methyl radical.

Question 34

What happens in termination?

Answer 34

Number of reaction occur to stop the chain reaction. All involve free radicals combining with each other to from molecules.

Question 35

What kind of reaction involves UV light?

Answer 35

Photochemical reaction.

Question 36

What is hydrolysis?

Answer 36

Chemical decomposition of a substance by water, the water itself also being decomposed.

Question 37

What is a polymer?

Answer 37

Very large molecule made up of many identical repeating units called monomers.

Question 38

What are halogenalkanes used in?

Answer 38

Fire extinguishers, refrigerants, pharmaceuticals and propellants.

Question 39

What is an addition reaction?

Answer 39

Reaction in which 2 substances react together to form a single substance.

Question 40

What is an elimination reaction?

Answer 40

Reaction in which a small molecule is removed from a larger molecule to leave a double bond in the larger molecule.

Question 41

How does an ionic addition reaction occur?

Answer 41

Step 1: polarisation- high conc. of negative charges. (Element) gets closer and becomes polarised. Step 2:- induced polarisation becomes so great the molecule splits. 2 electrons on 1 atom is heterolytic fission. Step 3: carbonium ion formation- (element) needs stability so attacks (compound). Forms covalent bond to a carbon. Other carbon has (+) charge. Step 4: Ionic addition- carbonium ion attacked by (element with (-) charge).

Question 42

What evidence proves free radical mechanism?

Answer 42

1. UV light of sufficient high energy is needed to break the bonds in chlorine moelcule, forming chlorine atoms. When a mixture of alkane and chlorine irradiated with UV light for a short period a chain reaction occurs. 2. Formation of ethane is evidence for termination 3. Reactions speeded up by adding known sources of free radical ie tetraethyllead