C6: Organic Chemistry Flashcards
Mnemonic for the different fractions of distilled petroleum
Real Great & Noble Kings Don’t Forget Ladies Birthdays
Sources of Hydrocarbons
Natural gas and petroleum
two types of cracking are:
-Thermal cracking -Catalytic cracking
Difference between thermal and catalytic cracking
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
importance of cracking hydrocarbons
- produce smaller more useful hydrocarbons such as petrol - produces alkenes which are used to make other useful organic compounds such as plastics
the 4 analogous groups in organic chemistry
alkanes alkenes alcohols(or Alkanols) Carboxylic acids or alkanoic acids
The functional group in alkanoic acids
-COOH
The functional group in the alkanols
-OH
Alkanoic acids are (1)______________ acids because they are (2)_____________ ionized in water.
(1) - weak (2) - partially
what does the R stand for in the following analogous groups R-OH and R-COOH
the hydrocarbon portion of the molecule
reactions of alkanes
-combustion -substitution reactions with the halogens
Reactions of alkenes
- combustion - addition reactions
addition reactions of Alkenes include:
- 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
two main reagents used to distinguish between alkanes and alkenes
reacting with bromine solution or acidified potassium manganate
what is the basis of the tests to differentiate between alkanes and alkenes?
to test for the presence of the carbon-carbon double bond.
how to differentiate between alkanes and alkenes
alkenes react readily with bromine solution and acidified potassium manganate solution. Alkanes do not react with either under normal conditions.
uses of alkanes
- fuel - solvents eg hexane and heptane
uses of alkenes
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
what is biogas
gas produced by anaerobic bacteria when they break down organic matter
main hydrocarbon in biogas is
methane(60%)
what is methane used for?
fuel for cooking, heating, and to generate electricity
what is biomethane?
purified methane
reactions of ethanol
- 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
reactions of aqueous ethanoic acid
- reacts with reactive metals - reacts with metal oxides and metal hydroxides - reacts with metal carbonates
definition of isomers
organic compounds with same molecular formulae but different structural formulae
isomerism can be either due to (1)__________ or (2)_________
(1) branching (2) position of the functional group
every isomer has its own ________
unique name
general physical properties of alcohols
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
how can much of the physical properties of alkanols be explained?
presence of the polar -OH goup
All alcohols are either (1)_____ or (2)___________ at room temperature but never (3)_________________
(1) liquids (2)solids (3)gas
How are esters formed?
Alcohol + carboxylic acid = ester + water
the reaction between alcohol and alkanoic acid is example of this type of reaction
condensation reaction
what is a condensation reaction?
when two molecules join to form a larger molecule with the loss of a water molecule
apart from the reactants, what does esterification need to occur successfully?
heat and conc. sulfuric acid
what is the role of sulfuric acid in esterification?
- catalyst - remove the water produced during the reaction
General formula for esters
R-COO-R’
what are the products of esterification?
ester and water
what is the functional group of esters?
-COO-
reactions of esters
- acid hydrolysis - alkaline hydrolysis
which type of hydrolysis produces soaps?
alkaline hydrolysis
Hydrolysis
is when larger molecules are broken down into smaller molecules by reacting the compound with water
difference between hydrolysis and cracking
- 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.
acid hydrolysis of esters
ester + water + dilute acid + heat gives alkanoic acid and alkanol. The acid acts as a catalyst
alkaline hydrolysis of esters
ester + alkali + heat gives a salt and alkanol.
saponification
process of producing soap
Soapy detergents
made by boiling animal fats or vegetable fats and oils with concentrated sodium hydroxide or potassium hydroxide solution
example of a soapy detergent
sodium octadecanoate, C17H35COONa
soapless detergents(synthetic detergents)
detergents made from petroleum.
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
1 - soapy 2- soapy 3- soapless 4- soapy 5- soapy 6- soapy 7- soapless 8- soapless 9-soapless 10- soapless 11 - soapy 12- soapless
what are polymers?
macromolecules made up of linking of at least 50 monomers
what is polymerization?
formation of polymers using monomers
the two types of polymerization
addition and condensation
types of reactions seen in organic chemistry
substitution, addition, condensation, hydrolysis, esterification, dehydration, saponification
addition polymers used to make many types of ____________
plastics
in condensation reactions what are the most common small molecules lost
water, ammonia, HCl,
more than one type of monomer combine in (1)______________ while only one type of monomer combine in (2)____________.
(1) condensation polymerization (2) addition polymerization
addition polymerization occurs when (1)__________ containing (2)___________ combine to form a polymer and no other product.
(1)monomers (2) C=C double bonds
condensation reaction
different monomers link + loss of small molecules mainly water
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
a - addition b - condensation c - condensation d - addition e - addition f - condensation g- condensation h - condenation i - addition j - condensation k - addition
