Organic chemistry- paper 2 Flashcards
What are Hydrocarbons?
. compound formed from carbon and hydrogen atoms only
Alkanes what series, and the general formula? 2
What is a homologue series?
1)Alkanes simplest type of hydrocarbon
general formula C n H 2n+2
2) alkanes=homologous series - a group of organic compounds that react in a similar way.
What are alkanes, and how many bonds do they have, what are the first four?
.Alkanes are saturated compounds - each carbon atom forms four single covalent bonds.
.first four alkanes are methane, ethane, propane and butane.
1)What controls the properties of hydrocarbons?
2) what are the properties of short HC (alkanes)? 3
3) what do the properties mean for their uses?
1)
length of the carbon chain
2)
Shorter the carbon chain:
-runny a hydrocarbon.
-volatile= lower boiling points. (easily evaporated
-flammable
3)
affect how they’re used for fuels
What is Complete Combustion? 2
3.Why are they fuels due to complete combustion?
1)hydrocarbon in oxygen releases lots of energy
waste product: co2, water
2) carbon and hydrogen from oxidised.
3.fuels due amount of energy released when combust completely.
What is the the hydrocarbon combustion formula?
How is Crude Oil made and what is it?
Crude oil=mixture different hydrocarbons=alkanes.
1) Crude oil fossil fuel. formed= remains plants,animals, plankton, millions years in mud.
2)high temperature and pressure=crude oil. drilled up from rocks.= Fossil fuels
What are finite resources?
.one day they’ll run out.
1) what is fractional distillation, what does each fraction contain?
2)What is Fractional Distillation and what can be Used? 4
1)different compounds in crude oil are separated by fractional distillation.
.Each fraction contain similar number carbon atoms= similar boiling points.
(2)
1)oil heated most turned into gas. enter fractionation column (bitumen drained off).
2)temperature gradient (hot bottom, cooler up).
3) longer hydrocarbons=high boiling point= condense back into liquids drain early on, bottom.
4)shorter hydrocarbons=lower boiling points. Condense, drain later on, top.
How is Crude Oil has Various Uses? 5
1)modern transport- cars, trains, planes.
2)petrochemical industry
3)oil feedstock, new compounds polymers, detergents.
What is a homologous series? 2
1)carbon atoms bond form different groups =homologous series.
2)groups similar compounds many properties in common.
Which is more useful longer, shorter hydrocarbons and why? 2
1)Short-chain hydrocarbon’s flammable=good fuels=high demand
2)long-chain hydrocarbons=thick gloopy liquids like tar
1)What is cracking and what is it’s used for?
2)how is cracking done what type of reaction is it?
1)longer alkane molecules produced from fractional distillation turned into smaller, in cracking.
2)thermal decomposition reaction - breaking molecules down by heating them
1)What are alkenes used for?
2) what can the products of cracking be use for short chain alkanes?
1)starting material making compounds, used to make polymers
2)useful as fuels
What is cracking? 2
What are the products?
1.larger saturated hydrocarbon molecules broken down smaller, useful hydrocarbon unsaturated
2.starting hydrocarbons are alkanes
products alkanes and alkenes,
Alakne= CnH2n+2
Aklene= CnH2n
What are Alkenes properties and the differences between alkanes? 4
Alkenes:
.double bond carbon atoms (1)
.fewer hydrogens
.unsaturated.
.reactive=double bond open=single bond,
What are the first four alkenes?
.ethene (with two carbon atoms),
.propene (three Cs),
.butene (four Cs)
.pentene (five Cs).
because of the double bond they can’t have an alkene with only one carbon
Why do Alkenes Burn With a Smoky Flame and what is the equation? 4
What is the results? 2
1)large amount oxygen= alkenes combust completely produce= water, co2
2) when you burn them=incomplete combustion.
3)Co2 and water produced, carbon and carbon monoxide=poisonous gas.
alkene + oxygen › carbon+ carbon monoxide + carbon dioxide + water (+energy)
3) smoky yellow flame, less energy released
Why do Alkenes React via Addition Reactions? 2
1) alkenes have functional group ‘C=C’, react similar
2)alkenes react via addition reactions. carbon-carbon double bond open up leave single bond and a new atom is added to each carbon
What is Addition of Hydrogen? 2
1)hydrogen and catalyst react with double-bonded carbons to open up double bond
2)form the equivalent, saturated, alkane.
How can Steam can React with Alkenes to Form Alcohols ? 6
-how to make ethanol
1)alkenes react steam, water added across double bond=alcohol
2)mixing ethene steam passing over a catalyst
3)passed from reactor into condenser.
4) Ethanol and water=higher boiling point then ethene, both condense
5)any unreacted ethene gas is recycled back into the reactor.
6) alcohol be purified mixture by fractional distillation.
How do Halogens can React with Alkenes? 2
How do you name them?
1)Alkenes (addition reactions) halogens e.g bromine, chlorine, iodine.=saturated, carbons bonded halogen atom.
2) bromine ethene react together to form dibromoethane:
dibromo
Dichloro
Diiodo
What are Addition Polymers? 3
1)monomers make up addition polymers double covalent bond.
2) Lots unsaturated monomer molecules (alkenes), open double bonds join together form polymer chains.=addition polymerisation.
3)monomers=product is polymer.
Alcohols naming system and functional group?
Alcohols general formula?
1)naming system: alkanes replace final ‘-e’ with ‘ol’
2)-OH functional group.
What are the first 4 in the homologous series of alcohols?
What are the First Four Alcohols Similar Properties? 5
What is the functional group?
ALCHOL PROPERTIES:
-flammable
-soluble in water=solutions neutral pH= as number carbon atoms increase solubility decrease
-undergo complete combustion in air=carbon dioxide and water.
-react with sodium=product hydrogen.
-Alcohols oxidised oxygen=carboxylic acid.
How can Ethanol can be Made by Fermentation? 4
what is the equation for fermination?
1) Fermentation enzyme in yeast convert sugars to ethanol= co2
2) Fermentation 37 °C, slightly acidic solution, under anaerobic conditions (no oxygen).
What is Carboxylic Acids functional group and what do the names end in? 2
The names of the first 4 Carboxylic Acids?
1)Carboxylic acids ‘COOH’ functional group.
2) end in ‘-anoic acid’
How do Carboxylic Acids and carbonate React to form? 2
Why do carboxylic acids react? 3
1) carboxylic acid + metal carbonate-> salt + water + carbon dioxide
2)salts/ions formed= end -anoate. E.g sodium ethanoate
WHY:
1)Carboxylic acids dissolve in water. ionise, release H+ ions resulting acidic solution.
2)don’t ionise completely (not all acid molecules release H* ions)= weak acidic solutions.
3)higher pH (less acidic) than aqueous solutions of strong acids same concentration.
How can Esters can be Made from Carboxylic Acids? 3
what is the equation for the esters?
1)Esters functional group ‘-COO-‘.
2) formed: alcohol+carboxylic acid.
3) acid catalyst used (e.g. concentrated sulfuric acid).
Ethly
How are Polymers Made by Condensation Polymerisation? 4
1)monomers different functional groups.
2) react together, bonds form between them=polymer chains
3) each new bond forms=small molecule (water) lost.
4) two different types of monomer
What 2 type of group do Amino Acids have?
What is a glycine?
1)amino acid two different functional groups
=basic amino group (NH2)
=acidic carboxyl group (COOH).
2)glycine=smallest, simplest amino acid
1)What can amino acids form and how?
2)What can an amino acid react with and to form what?
3)what happens with every new bond?
1) Amino acids=polymers=polypeptides (condensation polymerisation)
2) amino group amino acid react with acid group another=polymer chain.
3)molecule of water is lost.
