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