Organic Chemistry Flashcards
What is crude oil?
A mixture of hydrocarbons
What are hydrocarbons?
Mixtures made of covalently bonded hydrogen and carbon molecules
Why is crude oil a mixture?
The compounds aren’t chemically bonded together and are therefore easily separated
What is an alkane?
A family of hydrocarbons
What are the first four members of the alkanes?
Methane CH4
Ethane C2H6
Propane C3H8
Butane C4H10
What is a substance when it is described as having saturated bonds?
A substance that has no double bond
What is a homologous series?
A group of compounds that can all be represented by the same general formula
What is the general formula for alkanes?
Cn H2n+2
What is an isomer?
Two molecules that have identical molecular formulas but different structures
What are the isomers of butane?
Butane
2-Methyl propane
What different properties do isomers have compared to alkanes?
Lower boiling points because branching makes the molecule more compact and therefore decreases its SA. As a result, the inter molecular forces decrease as they depend on the SA.
What is the formula for complete combustion of alkanes?
Alkane + oxygen —> carbon dioxide + water
What happens when complete combustion of an alkane happens?
Lots of energy is released and the gas burns with a clear blue flame
What is the formula for incomplete combustion of an alkane?
Alkane + oxygen —> carbon + carbon monoxide + carbon dioxide + water
What happens when incomplete combustion of an alkane occurs?
Less energy is released and it isn’t safe because CO is poisonous. The gas burns with a smoky orange flame.
What is formed when a halogen reacts with an alkane?
Haloalkanes are formed
What conditions are required for a haloalkane to form?
UV light
What is the equation for methane and bromine reacting together?
Methane + bromine –> bromomethane + hydrogen bromide
CH4 + Br2 –> CH3Br + HBr
What kind of reaction occurs when a halogen reacts with an alkane?
A substitution reaction
What is the test for an alkane?
Alkane + bromine water —> remains orange
What is an alkene?
Hydrocarbons that have a double bond between two of the carbon atoms in their chain.
What is meant by an unsaturated molecule?
A molecule that has a double bond, so they’re more reactive than alkanes
What are the first three members of the alkenes?
Ethene C2H4
Propene C3H6
Butene C4H8
What is the general formula for the alkenes?
Cn H2n
What are the isomers of butene?
Butene
But-2-ene
2methylpropene
What is the test for alkenes?
Alkene + bromine water –> goes from orange to colourless
What happens when a halogen reacts with an alkene?
They form haloalkenes
What is the equation for ethene + bromine?
Ethene + bromine –> dibromoethane
C2H4 + Br2 –> C2H4Br2
What happens when ethene and bromine react together?
The C C double bond is split and a bromine atom is added to each of the carbons, so it is called an addition reaction.
What is the general formula for alcohols?
Cn H2n+1 OH
What are the first three members of the alcohols?
Methanol CH3 OH CH4O
Ethanol CH3 CH2 OH C2H6O
Propanol CH3 CH2 CH2 OH C3H8O
What are the isomers of butanol?
Butanol
Butan-2-ol
2-methyl propan-1-ol
2-methyl propan-2-ol
What are the two methods used to produce ethanol?
Fermentation
Hydration of ethene
What is the process of fermentation?
Yeast is added to a sugar/starch solution
It’s left in the warm (30-40°C) in anaerobic conditions
Enzymes in the yeast convert the sugar into ethanol and CO2