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Flashcards

halogens

megan trent A level Chemistry English 48 cards

halogens are the highly reactive non - mental of group 7

Cards in this deck (48)

  1. 1bleaching ability from Fluorine - iodine?decreases from fluorine - iodine
  2. 2trends in solubility from chlorine - iodine?decreases from chlorine - iodine
  3. 3iodine is almost insoluble in water but what is it soluble in?KI
  4. 4State and explain the change in melting points down group 7The melting point increases down the group because the number of electrons increases so the london forces also increase requiring more energy to overcome
  5. 5state and explain the change in electronegativity down group 7The electronegativity decreases as you go down the group as outer electrons are progressively more shielded from the nucleus as atomic radius increases, so the distance from the nucleus and bonding pair increases. Proton number increases so electrons in a covalent bond are attracted less to the halogen
  6. 6state and explain the change in reactivity of the group 7 elements down group 7As most reactions with halogens result in the halogen gaining an electron. they become less reactive on descending. Reactivity decreases as the atomic radius increases and more shielding.
  7. 7what is the problem with distinguishing between bromine and iodine solutions?They both look very similar as they are both clear pale yellow
  8. 8How could you show you have a solution of iodine?Add cyclohexane and shake, bromine will go dark orange and iodine will go purple
    using starch as it turns blue/black in the presence of iodine
  9. 9halogens are very good ...........?oxidising agents
    because they readily accept electrons
  10. 10The best oxidising agent?Cl2
  11. 11strongest reducing agent?2I-
  12. 12what is a disproptionation reaction ?when a substance is reduced and oxidised at the same time
  13. 13The reactions of halogens with cold alkaliAll halogens undergo a disproportionation reaction with cold alkali
  14. 14reactions of the halogens with hot alkaliThe chlorate ions themselves undergo disproportionation
  15. 15HCl and waterHCl gas is very soluble in water, reacting with it to produce hydrochloric acid. The familiar steamy fumes of hydrogen chloride in moist air are caused by the hydrogen chloride reacting with water vapour in the air to produce a fog of concentrated HCl
  16. 16are HBr/HI oxidising agents or reducing agents?reducing agents
  17. 17which is the stronger agent?HI
  18. 18test for chloride1. add Ag+ acidified with HNO3 - Produces white ppt
    2. Add excess NH3 to the above mixture - dissolves
    3. leave ppt in the light for 10 mins - White ppt turned lilac
  19. 19test for bromide1. add Ag+ acidified with HNO3 - Produces cream ppt
    2. Add excess NH3 to the above mixture - dissolves
    3. leave ppt in the light for 10 mins - cream ppt turned grey
  20. 20test for iodide1. add Ag+ acidified with HNO3 - Produces yellow ppt
    2. Add excess NH3 to the above mixture - doesn't dissolve
    3. leave ppt in the light for 10 mins - remains yellow
  21. 21suggest why dilute nitric acid was added to the silver nitrate solutionprevents precipitation of silver hydroxide, oxide or carbonate which would interfere with observations
  22. 22Flame testsLi+ -----> red
    Na+ -----> orange
    K+ -----> lilac
    Ba2+ -----> green
    Sr2+ -----> red
    Ca2+ -----> red/yellow
  23. 23Test for Mg2+Add NaOH
    observation: white ppt
  24. 24test for NH4+Add NaOH
    observation: The gas produced turns damp red litmus paper blue
  25. 25Test for Cl-1. adding a silver nitrate solution -- white ppt
    2. concentrated H2SO4 -- soluble in dilute sulphuric acid
  26. 26test for Br-1. adding a silver nitrate solution -- cream ppt
    2. concentrated H2SO4 -- steamy fumes of HBr + orange fumes of Br2
    3. To 2cm of sample add chlorine water -- solution turns orange
  27. 27test for I-1. adding a silver nitrate solution -- yellow ppt
    2. concentrated H2SO4 -- steamy fumes of HI and black solid I2
    3. To 2cm of sample add chlorine water -- solution turns brown
  28. 28test for SO42-add barium chloride -- white ppt
  29. 29test for CO32-Add acid and bubble gas through limewater --- fizzes and co2 is produced cloudy
  30. 30test for HCO32-add hot water bubble any gas through lime water --- if it goes cloudy
  31. 31halogens are the highly reactive non - mental of group 7halogens are the highly reactive non - mental of group 7
  32. 32halogens can displace halide ions from solutionhalogens can displace halide ions from solution
  33. 33halogen halide reactions are redox reactionshalogen halide reactions are redox reactions
  34. 34halogen halide reactions are redox reactions 2halogen halide reactions are redox reactions 2
  35. 35halogens can react with group 1 and group 2 metalshalogens can react with group 1 and group 2 metals
  36. 36halogens undergo disportionation with cold alkalihalogens undergo disportionation with cold alkali
  37. 37chlorine and sodium hydroxide male bleachchlorine and sodium hydroxide male bleach
  38. 38halogens also undergo disprortionation with hot alkalihalogens also undergo disprortionation with hot alkali
  39. 39chlorine is used to kill bacteria in waterchlorine is used to kill bacteria in water
  40. 40the reducing power of halides increases down the groupthe reducing power of halides increases down the group
  41. 41the reducing power of halides increases down the group which explains their reactions with sulphuric acid reaction of KF or KCl with H2SO4the reducing power of halides increases down the group which explains their reactions with sulphuric acid reaction of KF or KCl with H2SO4
  42. 42the reducing power of halides increases down the group which explains their reactions with sulphuric acid reaction of KBr with H2SO4the reducing power of halides increases down the group which explains their reactions with sulphuric acid reaction of KBr with H2SO4
  43. 43the reducing power of halides increases down the group which explains their reactions with sulphuric acid KI and H2SO4the reducing power of halides increases down the group which explains their reactions with sulphuric acid KI and H2SO4
  44. 44hydrogen halides are acidic gaseshydrogen halides are acidic gases
  45. 45silver ions great with halide ions to form a precipitatesilver ions great with halide ions to form a precipitate
  46. 46hydrochloric acid can help detect carbonateshydrochloric acid can help detect carbonates
  47. 47test for sulphates with HCl and Barium chloridetest for sulphates with HCl and Barium chloride
  48. 48use litmus paper and NaOH to test for ammonium compoundsuse litmus paper and NaOH to test for ammonium compounds

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A level Chemistry Flashcards on halogens, created by megan trent on 10/08/2018.
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megan trent
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