C6: Organic Chemistry

Question 1

Mnemonic for the different fractions of distilled petroleum

Answer 1

Real Great & Noble Kings Don’t Forget Ladies Birthdays

Question 2

Sources of Hydrocarbons

Answer 2

Natural gas and petroleum

Question 3

two types of cracking are:

Answer 3

-Thermal cracking -Catalytic cracking

Question 4

Difference between thermal and catalytic cracking

Answer 4

Thermal cracking uses temperatures of about 750 deg C and pressures of about 70atm. Catalytic cracking uses lower temperatures, about 500 degC and much lower pressures in the presence of a catalyst

Question 5

importance of cracking hydrocarbons

Answer 5

• produce smaller more useful hydrocarbons such as petrol - produces alkenes which are used to make other useful organic compounds such as plastics

Question 6

the 4 analogous groups in organic chemistry

Answer 6

alkanes alkenes alcohols(or Alkanols) Carboxylic acids or alkanoic acids

Question 7

The functional group in alkanoic acids

Answer 7

-COOH

Question 8

The functional group in the alkanols

Answer 8

-OH

Question 9

Alkanoic acids are (1)______________ acids because they are (2)_____________ ionized in water.

Answer 9

(1) - weak (2) - partially

Question 10

what does the R stand for in the following analogous groups R-OH and R-COOH

Answer 10

the hydrocarbon portion of the molecule

Question 11

reactions of alkanes

Answer 11

-combustion -substitution reactions with the halogens

Question 12

Reactions of alkenes

Answer 12

• combustion - addition reactions

Question 13

addition reactions of Alkenes include:

Answer 13

• addition of hydrogen to form alkanes - addition of water(steam) to form alcohols - addition of halogens and hydrogen halides to form haloalkanes - polymerization reactions to form polyalkenes - addition reaction with acidified potassium manganate to form dialcohols

Question 14

two main reagents used to distinguish between alkanes and alkenes

Answer 14

reacting with bromine solution or acidified potassium manganate

Question 15

what is the basis of the tests to differentiate between alkanes and alkenes?

Answer 15

to test for the presence of the carbon-carbon double bond.

Question 16

how to differentiate between alkanes and alkenes

Answer 16

alkenes react readily with bromine solution and acidified potassium manganate solution. Alkanes do not react with either under normal conditions.

Question 17

uses of alkanes

Answer 17

• fuel - solvents eg hexane and heptane

Question 18

uses of alkenes

Answer 18

they are the starter materials in the manufacture of many other compounds - to make ethanol and other alcohols and dialcohols - to make plastics - to make synthetic rubbers

Question 19

what is biogas

Answer 19

gas produced by anaerobic bacteria when they break down organic matter

Question 20

main hydrocarbon in biogas is

Answer 20

methane(60%)

Question 21

what is methane used for?

Answer 21

fuel for cooking, heating, and to generate electricity

Question 22

what is biomethane?

Answer 22

purified methane

Question 23

reactions of ethanol

Answer 23

• burns easily in air or oxygen - reacts with sodium to form sodium ethoxide - reacts with alkanoic acids to form esters - reacts with oxidizing agents to form ethanoic acid - undergoes dehydration to form ethene with conc. H2SO4 as catalyst

Question 24

reactions of aqueous ethanoic acid

Answer 24

• reacts with reactive metals - reacts with metal oxides and metal hydroxides - reacts with metal carbonates

Question 25

definition of isomers

Answer 25

organic compounds with same molecular formulae but different structural formulae

Question 26

isomerism can be either due to (1)\_\_\_\_\_\_\_\_\_\_ or (2)\_\_\_\_\_\_\_\_\_

Answer 26

(1) branching (2) position of the functional group

Question 27

every isomer has its own \_\_\_\_\_\_\_\_

Answer 27

unique name

Question 28

general physical properties of alcohols

Answer 28

alkanols are polar because of the presence of the OH group which is polar. - less volatile than corresponding alkanes - soluble in water because they are polar

Question 29

how can much of the physical properties of alkanols be explained?

Answer 29

presence of the polar -OH goup

Question 30

All alcohols are either (1)\_\_\_\_\_ or (2)\_\_\_\_\_\_\_\_\_\_\_ at room temperature but never (3)\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 30

(1) liquids (2)solids (3)gas

Question 31

How are esters formed?

Answer 31

Alcohol + carboxylic acid = ester + water

Question 32

the reaction between alcohol and alkanoic acid is example of this type of reaction

Answer 32

condensation reaction

Question 33

what is a condensation reaction?

Answer 33

when two molecules join to form a larger molecule with the loss of a water molecule

Question 34

apart from the reactants, what does esterification need to occur successfully?

Answer 34

heat and conc. sulfuric acid

Question 35

what is the role of sulfuric acid in esterification?

Answer 35

- catalyst - remove the water produced during the reaction

Question 36

General formula for esters

Answer 36

R-COO-R'

Question 37

what are the products of esterification?

Answer 37

ester and water

Question 38

what is the functional group of esters?

Answer 38

-COO-

Question 39

reactions of esters

Answer 39

- acid hydrolysis - alkaline hydrolysis

Question 40

which type of hydrolysis produces soaps?

Answer 40

alkaline hydrolysis

Question 41

Hydrolysis

Answer 41

is when larger molecules are broken down into smaller molecules by reacting the compound with water

Question 42

difference between hydrolysis and cracking

Answer 42

- Cracking breaks longer chained hydrocarbon into shorter chained hydrocarbons. It requires heat and a catalyst. - Hydrolysis is the breaking down of larger molecules into smaller molecules by reacting with water. Requires water as a reagent, catalyst and heat.

Question 43

acid hydrolysis of esters

Answer 43

ester + water + dilute acid + heat gives alkanoic acid and alkanol. The acid acts as a catalyst

Question 44

alkaline hydrolysis of esters

Answer 44

ester + alkali + heat gives a salt and alkanol.

Question 45

saponification

Answer 45

process of producing soap

Question 46

Soapy detergents

Answer 46

made by boiling animal fats or vegetable fats and oils with concentrated sodium hydroxide or potassium hydroxide solution

Question 47

example of a soapy detergent

Answer 47

sodium octadecanoate, C17H35COONa

Question 48

soapless detergents(synthetic detergents)

Answer 48

detergents made from petroleum.

Question 49

comparison of soapy and soapless detergents: 1 - renewable 2- form fats and oils 3- some are biodegradable 4- lather easily in hard water 5- formation of scum 6- all biodegradable 7- cause eutrophication 8- non-renewable 9- manufactured from petroleum 10- do not form scum 11- does not cause eutrophication 12- does not lather easily in hard water

Answer 49

1 - soapy 2- soapy 3- soapless 4- soapy 5- soapy 6- soapy 7- soapless 8- soapless 9-soapless 10- soapless 11 - soapy 12- soapless

Question 50

what are polymers?

Answer 50

macromolecules made up of linking of at least 50 monomers

Question 51

what is polymerization?

Answer 51

formation of polymers using monomers

Question 52

the two types of polymerization

Answer 52

addition and condensation

Question 53

types of reactions seen in organic chemistry

Answer 53

substitution, addition, condensation, hydrolysis, esterification, dehydration, saponification

Question 54

addition polymers used to make many types of \_\_\_\_\_\_\_\_\_\_\_\_

Answer 54

plastics

Question 55

in condensation reactions what are the most common small molecules lost

Answer 55

water, ammonia, HCl,

Question 56

more than one type of monomer combine in (1)\_\_\_\_\_\_\_\_\_\_\_\_\_\_ while only one type of monomer combine in (2)\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 56

(1) condensation polymerization (2) addition polymerization

Question 57

addition polymerization occurs when (1)\_\_\_\_\_\_\_\_\_\_ containing (2)\_\_\_\_\_\_\_\_\_\_\_ combine to form a polymer and no other product.

Answer 57

(1)monomers (2) C=C double bonds

Question 58

condensation reaction

Answer 58

different monomers link + loss of small molecules mainly water

Question 59

addition or condensation polymer? a- PVC b - cellulose c - polysaccharide d - teflon e - polypropene f - polyester g - starch h - nylon i - polystyrene j - polyamide k - polyethene

Answer 59

a - addition b - condensation c - condensation d - addition e - addition f - condensation g- condensation h - condenation i - addition j - condensation k - addition