Organics 1 - 4th Flashcards
what is crude oil?
- a mixture of hydrocarbons, compounds of hydrogen (H) and carbon (C) only
- the different hydrocarbons in crude oil come in a huge variety of shapes and sizes, which results in crude oil boiling over a very large range of temperatures
why do we need to separate crude oil?
- most of the hydrocarbons are useful, but often for very different purposes
- this means we need to separate the oil into fractions which contain similarly used molecules.
what is each fraction of crude oil?
- a mixture of similar hydrocarbons with similar boiling points
what happens to the fractions of crude oil as the boiling points increase?
- the fractions get darker in colour
- the fractions get more viscous (like treacle)
what happens to the fractions of crude oil as the boiling points increase?
- the fractions get darker in colour
- the fractions get more viscous (like treacle)
what is the boiling point, molecular mass, colour, viscosity and use of refinery gases?
- low BP
- low molecular mass
- light colour
- low viscosity
- used for fuel for home cooking
what is the use of gasoline?
- used for fuel for cars
what is the use of kerosene ?
- used for fuel for aircraft
what is the use of diesel?
- used for fuel for trains
what is the use of fuel oil?
- fuel for ships
what is the boiling point, molecular mass, colour, viscosity and use of bitumen?
- high BP
- high molecular mass
- dark colour
- high viscosity
- used for making roads
how are each of the fractions separated from crude oil?
- by fractional distillation
- done industrially on a large scale
how does fractional distillation work?
- fractionating column is hotter at the bottom and colder at the top
onenote chemistry rev pic
THIS IS HOW IT WORKS: - heated crude oil vapours enter the column
what is the order of each of the fractions from lowest to highest BP/order of fractional distillation?
- refinery gases
- gasoline
- kerosene
- diesel
- fuel oil
- bitumen
what are fractions?
- mixtures containing the hydrocarbons that boil in a particular temperature range
- for example, kerosene contains hydrocarbons that boil between 250 degrees and 350 degrees.
what are alkanes?
- hydrocarbons that fit the general formula C v nH v 2n+2
- (v means subscript)
- made of simple molecules containing C and H atoms held together by covalent bonds
how are alkanes named?
- the start of the name shows how many carbon atoms it has
- the end of the name is ‘-ane’ to show it is an alkane
what is the name and bonding of CH4?
- methane
- *chem rev image
what is the name and bonding of C2H6?
- ethane
- *chem rev image
what is the name and bonding of C3H8?
- propane
- *chem rev image
what is the name and bonding of C4H10?
- butane
- *chem rev image
what is the name and bonding of C5H12?
- pentane
- *chem rev image
what names of alkane bondings come after methane, ethane, propane, butane and pentane?
- names follow the 2d shapes
- hexane, heptane, octane, etc
what are the 4 types of formulae for each alkane?
- displayed formula
- structural formula
- molecular formula
- empirical formula
what does the displayed formula show?
- a diagram showing the position of every atom and every bond
- e.g. chemistry flashcard 21
what does the structural formula show?
- this shows the structure of the molecule in one line, read from left to right like a word
- e.g. CH3CH2CH2CH3
what does the molecular formula show?
- this only shows how many carbon and hydrogen atoms there are
- e.g. C4H10
what does the empirical formula show?
- this only shows the simplest whole-number ratio of carbon to hydrogen
- e.g. C2H5
what are alkanes in terms of homologous series?
- alkanes are a homologous series of organic molecules
what does a homologous series of organic molecules mean?`
- this means they are a family of molecules which have:
- similar chemical reaction
- trends in physical properties (e.g. boiling points, viscosity or colour)
- the same general formula
what are the other series in the IGCSE course ?
- alkanes
- alcohols
- carboxylic acids
- esters
what are isomers?
- isomers are molecules with the same molecular formula but different structural formulae