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Halogens
The document is a guide about the halogens for GCSE chemistry students. It discusses the key properties and trends within group VII of the periodic table. The guide covers topics such as physical appearances, boiling points, electronic configurations, atomic sizes, and reactivity trends. It also describes reactions of halogens with metals and displacement reactions between halides.
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Halogens
- 1. GROUP VIIGROUP VII TheHalogensThe Halogens A guide for GCSE studentsA guide for GCSE students KNOCKHARDY PUBLISHINGKNOCKHARDY PUBLISHING 20102010 SPECIFICATIONSSPECIFICATIONS
- 2. GROUP VIIGROUP VII INTRODUCTION ThisPowerpoint show is one of several produced to help students understand selected GCSE Chemistry topics. It is based on the requirements of the AQA specification but is suitable for other examination boards. Individual students may use the material at home for revision purposes and it can also prove useful for classroom teaching with an interactive white board. Additional Powerpoints, and the full range of AS and A2 Chemistry topics, are available from the KNOCKHARDY WEBSITE at... www.knockhardy.org.uk All diagrams and animations in this Powerpoint are original and created by Jonathan Hopton. Permission must be obtained for their use in any commercial work. All diagrams and animations in this Powerpoint are original and created by Jonathan Hopton. Permission must be obtained for their use in any commercial work.
- 3. CONTENTSCONTENTS • Introduction • Grouptrends • Group similarities • Reaction with metals • Displacement reactions • Summary • Quick quiz GROUP VIIGROUP VII
- 4. INTRODUCTIONINTRODUCTION F Cl Br I At THE HALOGENS OCCURIN GROUP VII OF THE PERIODIC TABLE Group 1 2 3 4 5 6 7 0
- 5. INTRODUCTIONINTRODUCTION F Cl Br I At THE HALOGENS OCCURIN GROUP VII OF THE PERIODIC TABLE THEY ARE NON-METALS AND HAVE ELECTRONIC CONFIGURATIONS JUST ONE ELECTRON SHORT OF THE NEAREST NOBLE GAS Group 1 2 3 4 5 6 7 0
- 6. GROUP PROPERTIESGROUP PROPERTIES GENERAL• non-metals • exist as separate diatomic molecules… eg Cl2 • have seven electrons in their outer shells • form negative ions with a 1- charge • reaction with metals and halides
- 7. GROUP PROPERTIESGROUP PROPERTIES GENERAL• non-metals • exist as separate diatomic molecules… eg Cl2 • have seven electrons in their outer shells • form negative ions with a 1- charge • reaction with metals and halides TRENDS • appearance • boiling point • electronic configuration • atomic size • ionic size • reactivity
- 8.
- 9. GROUP TRENDSGROUP TRENDS F2 Yellow Cl2 Green Br2 Red/brown I2 Grey GASGAS LIQUID SOLID Colour State (at RTP) APPEARANCEAPPEARANCE Yellow Green Red/brown PurpleVapour colour
- 10. GROUP TRENDSGROUP TRENDS INCREASESdown Group because more energy is required to separate the larger molecules. F2 Yellow Cl2 Green Br2 Red/brown I2 Grey GAS GAS LIQUID SOLID Colour State (at RTP) APPEARANCEAPPEARANCE BOILING POINTBOILING POINT F2 - 188 Cl2 - 34 Br2 58 I2 183Boiling point / °C Yellow Green Red/brown PurpleVapour colour
- 11. GROUP TRENDSGROUP TRENDS •electrons go into shells further from the nucleus F Cl Br I 2,7 2,8,7 2,8,18,7 2,8,18,18,7Configuration ELECTRONIC CONFIGURATIONELECTRONIC CONFIGURATION 9 17 35 53Atomic Number
- 12. GROUP TRENDSGROUP TRENDS FCl Br I ATOMIC & IONIC RADIUSATOMIC & IONIC RADIUS 0.064 0.099 0.111 0.128Atomic radius / nm NOT TO SCALE
- 13. GROUP TRENDSGROUP TRENDS ATOMICRADIUS INCREASES down Group IONIC RADIUS INCREASES down Group • the greater the atomic number the more electrons there are these go into shells increasingly further from the nucleus • ions are larger than atoms - the added electron repels the others so radius gets larger F Cl Br I ATOMIC & IONIC RADIUSATOMIC & IONIC RADIUS 0.064 0.099 0.111 0.128Atomic radius / nm F¯ Cl¯ Br¯ I¯ 0.136 0.181 0.195 0.216Ionic radius / nm
- 14.
- 15. GROUP SIMILARITIESGROUP SIMILARITIES •all the atoms have seven electrons in their outer shell • ions are larger than atoms - the added electron repels the others so radius gets larger ELECTRONIC CONFIGURATIONELECTRONIC CONFIGURATION F Cl Br I 2,7 2,8,7 2,8,18,7 2,8,18,18,7Configuration 9 17 35 53Atomic Number
- 16. GROUPGROUP SIMILARITIESSIMILARITIES MOLECULAR FORMULAMOLECULARFORMULA F Cl Br I Covalent Covalent Covalent CovalentBonding F2 Cl2 Br2 I2Molecular formula NOT TO SCALE • all exist as diatomic molecules
- 17. GROUPGROUP SIMILARITIESSIMILARITIES ION FORMATIONIONFORMATION F Cl Br I Configuration Ion F¯ Cl¯ Br¯ I¯ 2,8 2,8,8 2,8,18,8 2,8,18,18,8 • all gain one electron to form a negative ion of charge 1- • ions are larger than atoms • the smaller the atom the easier it forms an ion
- 18. GROUPGROUP SIMILARITIESSIMILARITIES ION FORMATIONIONFORMATION F Cl Br I Configuration Ion F¯ Cl¯ Br¯ I¯ 2,8 2,8,8 2,8,18,8 2,8,18,18,8 • all gain one electron to form a negative ion of charge 1- • ions are larger than atoms • the smaller the atom the easier it forms an ion REACTIVITYREACTIVITY F Cl Br I Reactivity Increasingly reactive • reactivity decreases down the Group / increases up the Group
- 19. REACTIONS OF HALOGENSREACTIONSOF HALOGENS 1. WITH METALS1. WITH METALS 2. WITH HALIDES2. WITH HALIDES
- 20. REACTION OF HALOGENSWITH METALSREACTION OF HALOGENS WITH METALS
- 21. REACTION OF HALOGENSWITH METALSREACTION OF HALOGENS WITH METALS HALOGENS REACT WITH METALS TO PRODUCE METAL HALIDES.
- 22. REACTION OF HALOGENSWITH METALSREACTION OF HALOGENS WITH METALS HALOGENS REACT WITH METALS TO PRODUCE METAL HALIDES. THE EASE OF REACTION DECREASES DOWN THE GROUP F > Cl > Br > I
- 23. REACTION OF HALOGENSWITH METALSREACTION OF HALOGENS WITH METALS HALOGENS REACT WITH METALS TO PRODUCE METAL HALIDES. THE EASE OF REACTION DECREASES DOWN THE GROUP F > Cl > Br > I THIS IS BECAUSE ‘THE LARGER THE HALOGEN ATOM, THE LESS EASILY IT ATTRACTS THE ELECTRON IT NEEDS TO FILL ITS OUTER SHELL’
- 24. REACTION OF HALOGENSWITH METALSREACTION OF HALOGENS WITH METALS HALOGENS REACT WITH METALS TO PRODUCE METAL HALIDES. THE EASE OF REACTION DECREASES DOWN THE GROUP F > Cl > Br > I THIS IS BECAUSE ‘THE LARGER THE HALOGEN ATOM, THE LESS EASILY IT ATTRACTS THE ELECTRON IT NEEDS TO FILL ITS OUTER SHELL’ THE HALIDES OF GROUP I ARE… WHITE IONIC SOLIDS VERY SOLUBLE IN WATER SODIUM CHLORIDE (NaCl) IS A TYPICAL GROUP I HALIDE
- 25. REACTION WITH ALKALIMETALSREACTION WITH ALKALI METALS
- 26. REACTION WITH ALKALIMETALS - EquationsREACTION WITH ALKALI METALS - Equations SODIUM CHLORINE SODIUM CHLORIDE+
- 27. REACTION WITH ALKALIMETALS - EquationsREACTION WITH ALKALI METALS - Equations Na + Cl2 NaCl SODIUM CHLORINE SODIUM CHLORIDE
- 28. REACTION WITH ALKALIMETALS - EquationsREACTION WITH ALKALI METALS - Equations Na + Cl2 NaCl SODIUM CHLORINE SODIUM CHLORIDE The equation doesn’t balance - multiply the formulae until it doesThe equation doesn’t balance - multiply the formulae until it does
- 29. REACTION WITH ALKALIMETALS - EquationsREACTION WITH ALKALI METALS - Equations 2Na + Cl2 2NaCl Na + Cl2 NaCl SODIUM CHLORINE SODIUM CHLORIDE Balanced equationBalanced equation
- 30. Cl SODIUM ATOM 2,8,1 Na CHLORINE ATOM 2,8,7 11protons; 11 electrons 17 protons; 17 electrons SODIUM CHLORIDE FORMATIONSODIUM CHLORIDE FORMATION
- 31. Cl SODIUM ION 2,8 Na CHLORIDE ION 2,8,8 bothspecies now have ‘full’ outer shells; ie they have the electronic configuration of a noble gas + 11 protons; 10 electrons 17 protons; 18 electrons SODIUM CHLORIDE FORMATIONSODIUM CHLORIDE FORMATION
- 32. Cl SODIUM ION 2,8 Na CHLORIDE ION 2,8,8 NaNa+ + e¯ 2,8,1 2,8 ELECTRON TRANSFERRED Cl + e¯ Cl¯ 2,8,7 2,8,8 + SODIUM CHLORIDE FORMATIONSODIUM CHLORIDE FORMATION
- 33. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS
- 34. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS HALOGENS GET LESS REACTIVE AS THE GROUP IS DESCENDED
- 35. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS HALOGENS GET LESS REACTIVE AS THE GROUP IS DESCENDED THIS DECREASE IN REACTIVITY DOWN THE GROUP CAN BE DEMONSTRATED USING DISPLACEMENT REACTIONS... A DISPLACEMENT REACTION IS WHERE ONE SPECIES TAKES THE PLACE OF ANOTHER IN A COMPOUND.
- 36. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS SODIUM CHLORIDE SOLUTION Colourless SODIUM BROMIDE SOLUTION Colourless SODIUM IODIDE SOLUTION Colourless CHLORINE WATER Pale green BROMINE WATER Orange A SOLUTION OF THE HALOGEN IS ADDED TO A SOLUTION OF A HALIDE HALIDES ARE SALTS FORMED BETWEEN ELEMENTS AND HALOGENS
- 37. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS SODIUM BROMIDE SOLUTION Colourless SODIUM IODIDE SOLUTION Colourless CHLORINE WATER Pale green BROMINE WATER Orange SODIUM CHLORIDE SOLUTION Colourless NO VISIBLE REACTION Experiment 1
- 38. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS SODIUM CHLORIDE SOLUTION Colourless SODIUM IODIDE SOLUTION Colourless BROMINE WATER Orange CHLORINE WATER Pale green SODIUM BROMIDE SOLUTION Colourless BROMINE produced Experiment 2
- 39. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS SODIUM CHLORIDE SOLUTION Colourless SODIUM BROMIDE SOLUTION Colourless BROMINE WATER Orange CHLORINE WATER Pale green SODIUM IODIDE SOLUTION Colourless IODINE produced Experiment 3
- 40. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS SODIUM BROMIDE SOLUTION Colourless SODIUM IODIDE SOLUTION Colourless CHLORINE WATER Pale green BROMINE WATER Orange SODIUM CHLORIDE SOLUTION Colourless NO VISIBLE REACTION Experiment 4
- 41. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS SODIUM CHLORIDE SOLUTION Colourless SODIUM IODIDE SOLUTION Colourless CHLORINE WATER Pale green BROMINE WATER Orange SODIUM BROMIDE SOLUTION Colourless NO VISIBLE REACTION Experiment 5
- 42. DISPLACEMENT REACTIONS OFHALOGENSDISPLACEMENT REACTIONS OF HALOGENS SODIUM CHLORIDE SOLUTION Colourless SODIUM BROMIDE SOLUTION Colourless CHLORINE WATER Pale green BROMINE WATER Orange SODIUM IODIDE SOLUTION Colourless IODINE produced Experiment 6
- 43. SODIUM CHLORIDE CHLORINE SODIUM BROMIDESODIUM IODIDE Solution stays colourless NO REACTION Solution goes from colourless to orange- yellow NO REACTION Solution goes from colourless to orange- yellow BROMINE FORMED Solution goes from colourless to orange- yellow NO REACTION Solution goes from colourless to red IODINE FORMED BROMINE Solution goes from colourless to orange- red IODINE FORMED DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS SUMMARY OF OBSERVATIONS 1 65 2 3 4 The colour change in Experiments 4 and 5 is due to dilution – there is no reaction
- 44. CHLORINE + SODIUMBROMIDE CHLORINE + SODIUM IODIDE BROMINE + SODIUM IODIDE DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EQUATIONS
- 45. CHLORINE + SODIUMBROMIDE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM IODIDE IODINE + SODIUM CHLORIDE BROMINE + SODIUM IODIDE IODINE + SODIUM BROMIDE DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EQUATIONS
- 46. CHLORINE + SODIUMBROMIDE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM IODIDE IODINE + SODIUM CHLORIDE BROMINE + SODIUM IODIDE IODINE + SODIUM BROMIDE DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EQUATIONS Cl2(aq) + NaBr(aq) —> Br2(aq) + NaCl(aq) The equation doesn’t balance - multiply the formulae until it doesThe equation doesn’t balance - multiply the formulae until it does
- 47. CHLORINE + SODIUMBROMIDE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM IODIDE IODINE + SODIUM CHLORIDE BROMINE + SODIUM IODIDE IODINE + SODIUM BROMIDE DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EQUATIONS Cl2(aq) + 2NaBr(aq) —> Br2(aq) + 2NaCl(aq) Cl2(aq) + NaBr(aq) —> Br2(aq) + NaCl(aq)
- 48. CHLORINE + SODIUMBROMIDE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM IODIDE IODINE + SODIUM CHLORIDE BROMINE + SODIUM IODIDE IODINE + SODIUM BROMIDE DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EQUATIONS Cl2(aq) + 2Br¯(aq) —> Br2(aq) + 2Cl¯(aq) Cl2(aq) + 2NaBr(aq) —> Br2(aq) + 2NaCl(aq) IONIC EQUATION
- 49. CHLORINE + SODIUMBROMIDE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM IODIDE IODINE + SODIUM CHLORIDE BROMINE + SODIUM IODIDE IODINE + SODIUM BROMIDE DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EQUATIONS Cl2(aq) + 2I¯(aq) —> I2(aq) + 2Cl¯(aq) Cl2(aq) + 2NaI(aq) —> I2(aq) + 2NaCl(aq) IONIC EQUATION
- 50. CHLORINE + SODIUMBROMIDE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM IODIDE IODINE + SODIUM CHLORIDE BROMINE + SODIUM IODIDE IODINE + SODIUM BROMIDE DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EQUATIONS Br2(aq) + 2I¯(aq) —> I2(aq) + 2Br¯(aq) Br2(aq) + 2NaI(aq) —> I2(aq) + 2NaBr(aq) IONIC EQUATION
- 51. CHLORINE + SODIUMBROMIDE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM IODIDE IODINE + SODIUM CHLORIDE BROMINE + SODIUM IODIDE IODINE + SODIUM BROMIDE THIS SHOWS THAT A MORE REACTIVE HALOGEN WILL DISPLACE A LESS REACTIVE ONE FROM AN AQUEOUS SOLUTION OF ITS SALT DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS SUMMARY
- 52. CHLORINE + SODIUMBROMIDE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM IODIDE IODINE + SODIUM CHLORIDE BROMINE + SODIUM IODIDE IODINE + SODIUM BROMIDE THIS SHOWS THAT A MORE REACTIVE HALOGEN WILL DISPLACE A LESS REACTIVE ONE FROM AN AQUEOUS SOLUTION OF ITS SALT HOWEVER, THIS REACTION DOES NOT TAKE PLACE BROMINE + SODIUM CHLORIDE CHLORINE + SODIUM BROMIDE (Bromine is below chlorine in the Group so is less reactive) DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EQUATIONS
- 53. PRESS THE SPACEBAR TO SEE WHAT HAPPENS DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EXPLANATION 17+ CHLORINE ATOM 17 PROTONS 17 ELECTRONS 2,8,7 35+ BROMIDE ION 35 PROTONS 36 ELECTRONS 2,8,18,8 THE CHLORINE ATOM PULLS AN ELECTRON OUT OF THE OUTER SHELL OF THE BROMIDE ION – THE CHLORINE ATOM BECOMES A CHLORIDE ION AND THE BROMIDE ION BECOMES A BROMINE ATOM.
- 54. BECAUSE BROMINE ATOMSARE LARGER THAN CHLORINE ATOMS, IT IS EASIER TO PULL ONE OF THEIR OUTER SHELL ELECTRONS OUT. CHLORINE NOW HAS THE OUTER SHELL ELECTRONIC CONFIGURATION OF A NOBLE GAS. DISPLACEMENT REACTIONS OF HALOGENSDISPLACEMENT REACTIONS OF HALOGENS EXPLANATION CHLORINE ATOM 17 PROTONS 17 ELECTRONS BROMIDE ION 35 PROTONS 36 ELECTRONS CHLORIDE ION 17 PROTONS 18 ELECTRONS BROMINE ATOM 35 PROTONS 35 ELECTRONS
- 55. SYMBOL MOLECULAR FORMULA APPEARANCE STATE (room temp) F PALEYELLOW GAS Cl FLUORINE IODINE ELECTRONIC CONFIGURATION BOILING POINT 2,7 INCREASES 2,8,7 GAS ION (electronic config) F¯ 2,8 Cl¯ 2,8,8 REACTION WITH SODIUM LESS REACTIVE PRODUCT OF REACTION WITH SODIUM SODIUM FLUORIDE (NaF) SODIUM CHLORIDE (NaCl) PALE GREEN Br I BROMINECHLORINE F2 Cl2 Br2 I2 RED-BROWN GREY-BLACK LIQUID SOLID 2,8,18,7 2,8,18,18,7 Br¯ 2,8,18,8 I¯ 2,8,18,18,8 SODIUM BROMIDE (NaBr) SODIUM IODIDE (NaI) GROUP VII - SUMMARYGROUP VII - SUMMARY COLOUR OF VAPOUR PALE YELLOW GREEN RED-BROWN PURPLE
- 56. QUICK QUIZQUICK QUIZ 1.ELEMENTS IN GROUP 7 ARE KNOWN AS THE ……… 2. WHAT ARE THE NAMES OF THE ELEMENTS 3. HOW DOES THE ATOMIC NUMBER CHANGE DOWN THE GROUP? 4. HOW DOES THE ELECTRONIC CONFIGURATION CHANGE? 5. HOW DOES THE ATOMIC SIZE (RADIUS) CHANGE? 6. HOW MANY ELECTRONS DO THEY HAVE IN THE OUTER LEVEL? 7. ARE THEY METALS OR NON-METALS? 8. WHAT HAPPENS TO THEIR COLOUR DOWN THE GROUP? 9. DO THEY GO AROUND IN PAIRS OR AS MONATOMIC GASES? 10. WHAT HAPPENS TO THEIR STATE AT ROOM TEMPERATURE? 11. WHAT TYPE OF COMPOUNDS DO THEY FORM WITH METALS? 12. HOW CAN EXPLAIN THEIR RELATIVE REACTIVITY IN TERMS OF THE ATOMIC STRUCTURE?
- 57. QUICK QUIZ -ANSWERSQUICK QUIZ - ANSWERS 1. HALOGENS. 2. FLUORINE, CHLORINE, BROMINE, IODINE, ASTATINE. 3. ATOMIC NUMBER INCREASES DOWN THE GROUP. 4. GET MORE SHELLS DOWN THE GROUP. 5. ATOMIC SIZE INCREASES DOWN THE GROUP. 6. THEY ALL HAVE SEVEN ELECTRONS IN THE OUTER LEVEL. 7. THEY ARE NON-METALS. 8. COLOUR DARKENS DOWN THE GROUP. 9. ATOMS GO AROUND IN PAIRS OR AS DIATOMIC GASES. 10. GO FROM GAS TO SOLID DOWN THE GROUP. 11. THEY FORM IONIC COMPOUNDS WITH METALS. 12. THE LARGER THEY ARE THE LESS EASILY ELECTRONS ARE GAINED AND THE LESS REACTIVE THEY BECOME.
- 58. GROUP VIIGROUP VII TheHalogensThe Halogens THE ENDTHE END © 2011© 2011 KNOCKHARDY PUBLISHING & JONATHAN HOPTONKNOCKHARDY PUBLISHING & JONATHAN HOPTON