AS chemistry unit one point four

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AS chemistry unit one point four
2013-12-30 08:09:59
introduction organic chemistry

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  1. define empirical formula
    the simplest whole number ratio in which atoms in a compound combine together
  2. define molecular formula
    a formula that tells us the number of atoms of each different element that make up a molecule of a compound
  3. define structural formula
    a way of writing the formula of an organic compound in which bonds are not shown but each carbon atom is written separately with the atoms or groups of atoms attached to it e.g. butane-2-ol is written CH3CH2CH(OH)CH3
  4. Define displayed formula
    the formula of a compound drawn out so that each atom and each bond is shown
  5. define homologous series
    a set of organic compounds with the same functional group . the compounds differ in the length of their hydrocarbon chains
  6. define functional group
    an atom or group of atoms in an organic molecule which is responsible for characteristic reactions for that molecule
  7. what is an isomer
    one of two or more compounds with the same molecular formula but different structural formula i.e. the same atoms are arranged differently in space
  8. organic chemistry is the
    study of compounds containing carbon combined with other elements
  9. carbon is an unusual element which has the ability to
    form chain and ring structures by joining carbon atoms together . this ability means that a very large number of organic compounds exist
  10. for unit one you need to be familiar with three different homologous series
    • alkanes 
    • alkenes
    • haloalkanes 
    • however it's useful to know about 
    • alcohols , aldehydes , ketones , carboxylic acids , (primary) amines and nitriles too
  11. functional groups 
    functional group - name 
    alkane - a
    alkene - b
    haloalkane - c
    • a) -ane 
    • b) -ene 
    • c) bromo- , chloro- , iodo-
  12. number of C atoms - name 

    • meth 
    • eth
    • prop 
    • but 
    • pent
    • hex
  13. side chains 
    number of C atoms - structure - name 
    1                           - b            - c 
    2                           - d            - e
    3                           - f             - g
    • b) -CH3
    • c) - methyl 
    • d) CH2CH
    • e) ethyl 
    • f) CH2CH2CH3
    • g) propyl 
    • ... butyl , pentyl , hexyl 

  14. number of identical side chains 

    • di 
    • tri
    • tetra
  15. name - methane 
    homologous series - 
    molecular formula -
    structural formula - 
    empirica formula - 
    displayed formula
    • alkane
    • CH4
    • CH4
    • CH4
  16. name - ethane 
    homologous series - 
    molecular formula - 
    structural formula - 
    empirical formula - 
    displayed formula -
    • alkane 
    • C2H6
    • CH3CH3
    • CH3
  17. propane 
    homologous series - 
    molecular formula - 
    structural formula - 
    empirical formula - 
    displayed formula -
    • alkanes 
    • C3H
    • CH3CH2CH
    • C3H8
  18. name the first 6 alkanes
    • methane
    • ethane 
    • propane 
    • butane
    • pentane 
    • hexane
  19. the alkanes are
    hydrocarbons - this means they only contain carbon and hydrogen atoms
  20. what type of bond do alkanes have between the carbon atoms
    single covalent
  21. alkanes have the general formula
  22. the alkanes all have names ending in
  23. for straight chain alkanes the beginning of the name tells you
    the number of carbon atoms in the chain
  24. if the chain is branched it's said to have a
    side chain
  25. the side chain is named
    methyl , ethyl etc depending on the number of carbon atoms it contains . this is then put in front of the main chain .
  26. for example methylbutane has
    a main chain of four carbon atoms and a side chain of one carbon atom
  27. if there is more than one position that the side chain could attach to the min chain then
    it is given a number . this is counted from the end of the chain in order to make the number of the side chain as small as possible . remember the chain is the same backwards so for example if there are 3 main carbon atoms and the side chain was attached to the 3rd carbon atom the number would be 1
  28. if more than one side group of the same kind is attached to the chain then
    the prefix di- , tri- etc. is used in front of the name of the side chain
  29. here is the structure of an organic compound name it and write down the molecular formula and structural formula 
    what is the other displayed formula
    • 3-ethyl-2-methylpentane
    • CH3CH2CH(C2H5)CH(CH3)CH3
  30. give the displayed and structural formula for 2-methlybutane
    • CH3CH(CH3)CH2CH3
  31. give the structural , molecular and displayed formula for 2,3-dimethylpentane
    • CH3CH(CH3)CH(CH3)CH2CH3
    • C7H16
  32. the alkenes are also
    hydrocarbons like the alkanes
  33. alkenes have a .......... between two of the carbon atoms
    a double covalent bond
  34. alkenes have the general formula
    • CnH2n
  35. the alkenes are named in the same way as the alkanes except that
    their name ends in -ene . The position of the C=C double bond is numbered if there is more than one place where it can go in a molecule . The numbering is such that it has the smallest number possible
  36. what is the structural , displayed  , molecular formula and empirical of ethene
    • CH2=CH

    • C2H
    • CH2
  37. write down the molecular formula , displayed formula , structural formula and empirical formula of 3-methylbut-ene
    • CH2=CH(CH3)CH3
    • C5H10
  38. but-2-end displayed formula
  39. but-1-end displayed formula
  40. the functional group for alkenes is
  41. the haloalkanes are
    compounds containing carbon , hydrogen and a halogen atom
  42. haloalkanes have the general formula
    CnH2n+1X where X is a halogen atom
  43. displayed formula for chloromethane
  44. displayed formula 2-bromobutane
  45. displayed formula 1 chloropropane and 2 chloropropane
  46. if the halogen has more than one of the same halogen atom then
    the halogen is numbered di- , tri- , tetra- etc as with the side chains in alkanes
  47. isomerism occurs
    when two or more organic molecules have the same molecular formula but different arrangements of atoms
  48. the type of isomerism that we deal with in unit 1 is
    structural isomerism
  49. structural isomerism occurs when
    two or more organic molecules have the same molecular formula but different structural formula
  50. there are 3 types of structural isomerism
    • chain isomerism 
    • position isomerism 
    • functional group isomerism
  51. chain isomerism occurs when
    two or more molecules have the same molecular formula but different arrangements of the carbon chain . typically this will involve straight chain and branched chain structures
  52. for example there are two chain isomers of C4H10 , as the carbon atoms can be arranged in a straight chain forming ....... or as ....................
    • butane or as a chain of three  carbon atoms with one side chain forming 2-methyl propane
  53. for C5H12 there are 3 possible chain isomers
    • the carbon atoms can be arranged in a straight chain forming pentane , as a chain of four atoms with a side chain forming methyl butane or as a chain of 3 atoms with 2 side chains forming dimethylpropoane
  54. chain isomers are isomers where the
    chain remains the same but the position changes
  55. C4H8Cl2 has 6 possible position isomers
    • CH3CH2CH2Cl
    • CH3Cl2CH2CH3
    • CH2ClHClCH2CH3
    • CH2ClCH2CH2CH2Cl
    • CH2ClCH2CHClCH3
    • CH3CHClCHClCH3
    • we have had 1-1 dichlorobutane , 2-2 dichlorobutane , 1-2 dichlorobutane , 1-4 dichlorbutane , 1-3 dichlorobutane and 2-3 dichlorobutane . there are also possible chain isomers which haven't been drawn 
  56. positional isomerism occurs when
    a functional group can be in more than one position on the carbon chain
  57. you must consider positional isomerism when
    the molecule contains a chain of four or more carbon atoms or when the functional group is a halogen which can be in different positions on the chain
  58. there are 3 possible functional group isomers of C3H6O
    • CH3COCH3 which is propanone which is a ketone 
    • CH3CH2CHO which is propanal which is an aldehyde 
    • CH2=CHCH2OH which is pro pen-3-ol which is an alkene/alcohol
  59. C4H8 has 2 position isomers , 1 functional group isomer and 1 chain isomer
    but-1-ene (position isomer)but-2-ene (position isomer)

     cyclobutane (functional group isomer) 

    • methylpropene (chain isomer)
  60. but-2-ene also shows a different type of isomerism called
    stereoisomerism only in chem 2 and chem 4