Topic 7 - Organic Chemistry

Cards (128)

  • What is a hydrocarbon?
    A hydrocarbon is any molecule that contaisn only carbon and hydrogen atoms
  • What is an alkane?
    An alkane is a hydrocarbon. It consits of a chain of carbon atoms surrounded by hydrogen and has the general formula of Cn H2n+2 where n is the number of carbon atoms
  • What is the formula for Methane
    CH4
  • What is teh formula for ethane
    C2H6
  • What is the formula for propane
    C3H8
  • What is the formula for butane?
    C4H10
  • Why is an alkane saturated?
    Because all of its atoms are bonded to as many other atoms as they can
  • How many bonds can carbon form?
    4
  • How many bonds can hydrogen form?
    1
  • What are the three trends in the properties of hydrocarbons?
    The shorter the molecuse the less viscous it is (it is more runny)The shorter the molecule the lower the boiling point isThe shorter the molecule, the more flammable the hydrocarbon is
  • What is the general equation for the combustion of a hydrocarbon?
    hydrocarbon + oxygencarbon dioxide + water vapour
  • What is crude oil?
    Crude oil is a mixture of many compounds, most of which are hydrocarbons. Most of the hydrocarbons in crude oil are alkanes
  • How is crude oil formed?
    Crude oil is mainly formed from the remains of plankton, plants and animals that are compressed at high temperatures and pressures for millions of years
  • How is crude oil seperated into different hydrocarbons?
    By fractional distillation
  • How does fractional distillation seperate crude oil?
    The crude oil is first turned into a gas and is then pumped into the bottom of a fractionating columnThe different hydrocarbons have different boiling points so condense and lave the fractionating collumn t different points up itShorter chains leave the collumn higher up as they have a lower boilin point
  • What are the uses of the hydrocarbons that leave the fractionating collumn and when do they leave?
  • What are the six uses for fractions and where do they exit the collumn?
  • How does the petrochemical industry use hydrocarbons?
    They use some hydrocarbons as feedstock to make new compounds to be used in making useful things
  • Give 4 things the petrochemical industry uses hydrocarbons to make
    lubricantssolventspolymersdetergents
  • What is a homologous series?
    A homologous series is series of compounds which: have the same general formula and have similar chemical properties
  • What is an organic compound?
    A compound that contains carbon atoms
  • What is cracking?
    Cracking is a process used to convert long chain hydrocarbons into shorter, more useful chains
  • Why are short chain hydrocarbons more useful than longer ones?
    They are flammable so make better fuels
  • What ar ethe two methods of cracking?
    Catalyctic cracking steam cracking
  • How does catalyctic cracking work?
    The long chai hydrocarbons are heated so they become a gasThe vapour is passed over a hot catalyst which splits the hydrocarbons apart
  • How does steam cracking work?
    The long chain hydrocarbons are heated so they become a gasThe vapour is mixed with steam and heated to a very high temperature which splits the hydrocarbons
  • What type of reaciton is cracking?
    thermal decomposition
  • An alkene is an unsaturated hydrocarbon.There are more reactive than alkanes. They have a double covalent bond between two of the carbon atoms in their chain
  • Why are alkenes unsaturated?
    they contain 2 fewer hydrogen atoms than an alkane of the same number of carbon atoms
  • What is the general formula for an alkene?
    CnH2n
  • What si the formula for ethene
    C2H4
  • What is the formula for propene
    C3H6
  • What is the formula for butene
    C4H8
  • What is the formula for pentene
    C5H10
  • How can you test for alkenes?
    Add bromine water to an alkene and it will become colourless. Adding it to an alkane it would remian ornage
  • What is the general equation for the incomplete combustion of alkenes?
    alkene + oxygen →carbon (soot)+carbon monoxide + water + carbon dioxide
  • What type of combustion do alkenes undergo in air and why?
    Incomplete combustion. There is not enough oxygen present in the air
  • What happens during an incomplete combustion reaction of an alkene?
    A smoky yellow flame and less energy being released
  • How do alkenes burn in air
    With a smoky yellow flame. They undergo incomplete combustion as there is not enough oxygen in the air
  • What is a functional group
    A group of atoms in the compiund that determine how the compound typically reacts