2. „ Instant Chemistry“ Viktor Obendrauf (Graz, Austria) viktor@obendrauf.com TEACHING CHEMISTRY WITH SMALL SCALE AND MICROSCALE GAS REACTIONS INCLUDING EXPLOSIONS International Christian University, Tokyo August 16 -18 2007 Chemical Society of Japan, Tokyo Japan ICU Foundation (JICUF)

3. V.O. are as safe as possible for the teacher and the students are as safe as possible for the teacher and the students are time-saving (preparation, performing, clean up) are time-saving (preparation, performing, clean up) are non-polluting to the environment (reduction of waste) are non-polluting to the environment (reduction of waste) are as safe as possible for the teacher and the students are as safe as possible for the teacher and the students are time-saving (preparation, performing, clean up) are time-saving (preparation, performing, clean up) are non-polluting to the environment (reduction of waste) are non-polluting to the environment (reduction of waste)

4. V.O. are cost-saving (materials, chemicals) are cost-saving (materials, chemicals) can be referred to the every day life can be referred to the every day life can be used to illustrate chemical theory can be used to illustrate chemical theory are cost-saving (materials, chemicals) are cost-saving (materials, chemicals) can be referred to the every day life can be referred to the every day life can be used to illustrate chemical theory can be used to illustrate chemical theory

5. V.O. Is it really necessary to have a fume hood for hazardous gases even involving very small amounts of substances? Is it really necessary to have a fume hood for hazardous gases even involving very small amounts of substances? Oh, so many fixing stands! But what‘s about the reaction?

6. V.O. Is it really necessary that chemical demonstrations must be performed at the teacher‘s table exclusively? Is it really necessary that chemical demonstrations must be performed at the teacher‘s table exclusively? What‘s about the safety shield?

7. V.O. Is it possible to use the same material with the same size for chemical demonstrations and for student‘s activities? Is it possible to use the same material with the same size for chemical demonstrations and for student‘s activities? Do we have hands-on experiments only for physics teaching? Do we have hands-on experiments only for physics teaching? Is it possible to use the same material with the same size for chemical demonstrations and for student‘s activities? Is it possible to use the same material with the same size for chemical demonstrations and for student‘s activities? Do we have hands-on experiments only for physics teaching? Do we have hands-on experiments only for physics teaching? What‘s about the safety shield?

8. V.O. * Would it be convenient to change demonstrations to microscale to perform gas experiments closer to the students? Oh, so many fixing stands! But what‘s about the reaction?

9. V.O. Is it possible to use a portable apparatus which needs no fixing stands? Is it possible to use a portable apparatus which needs no fixing stands? Oh, so many fixing stands! But what‘s about the reaction?

10. Select your 2 most favourite wishes in this list of 5 wishes What do Chemistry teachers really want? ( Results of an inquiry among 2000 Chemistry teachers) Percent (response from 632 colleagues in autumn 1999)

11. V.O.

12. Chemical experiments are an essential part of chemical education. Could it be, that a very time-consuming experiment is mainly food for the playing instinct of the teacher ? Could a time-consuming experiment be rather boring and useless for improving the knowledge of the students ? Is there enough time to teach, to discuss and to repeat the chemical background and contexts ?

13. INSTANT CHEMISTRY Two Criteria for Chemical Hands-on: Time-saving: The experiment should be done within a couple of minutes including clean up.Time-saving: The experiment should be done within a couple of minutes including clean up. Cost-saving: The experiment should involve familiar and cheap every day common material.Cost-saving: The experiment should involve familiar and cheap every day common material.

14. INSTANT CHEMISTRY Examples involving Chlorine Hydrogen, Acetylene, Oxygen, Ammonia

15. Well known problems with classical generation of gases

16. 0 0 +1 -1 0 0 +1 -1 Na + ½ Cl 2  NaCl

17. Large Scale ? Complicated arrangements too far away from the students Time-consuming (preparation, clean up) Expensive material Great demand of chemicals because of big flasks containing air Noisy and bad positioned fume hoods Generation of waste

18. 0 0 +1 -1 0 0 +1 -1 Chlorine: ½ Cl 2 + Na  NaCl What about going Smallscale or Microscale without changing the system?

19. Smallscale or Microscale ? 0 0 +1 -1 0 0 +1 -1 Chlorine: ½ Cl 2 + Na  NaCl Danger and Disadvantages: Complicated arrangements Fixed at the teacher‘s table Rather time-consuming (preparation, clean up) Expensive material

20. Test tube (Fiolax 16/160mm) Rubber stopper Verneret (soft material, 18D) 2 Needles in the stopper (1,2/40 mm; tips cut) 1 Syringe Normject 2mL (prepared for hard to move) 1 Syringe ONCE 20 ml (plunger rubber greased with special silicon oil) 1 Syringe 10 ml filled with activated charcoal in grains v.o. Low Cost Generator for various Gases V.O. ©

21. Rubber stopper Verneret 18D Test tube Fiolax 16/160 mm 2 Needles 1,2/40 mm 2ml syringe (plunger hard to move) 20ml syringe ONCE (plunger greased with special silicon oil) Cut tips V.O. ©

22. Gas kit I V.O. ©Gas kit II V.O. ©

23. Low-cost – Generation of Cl 2 KMnO 4 (s) HCl conc. Mn 2+ (aq) Mn 2+ (aq) Cl 2 -storage ++ Cl 2 (g)

24. V.O.

26. 0 0 +1 -1 0 0 +1 -1 Sodium chloride ½ Cl 2 + Na  NaCl Reaction product + 1 drop of water on a microscope slide water evaporated, stereo microscope 40 times +FLEXCAM

27. Low-cost – Generation of H 2 Zn (s) HCl conc. Zn 2+ (aq) + 2 Cl - (aq) Zn 2+ (aq) + 2 Cl - (aq) H 2 -storage ++ H 2 (g)

28. Test tube Fiolax 16/160Test tube Fiolax 16/160 15 ml Hydrogen15 ml Hydrogen Procedure:Procedure: 15 ml Hydrogen are injected into the test tube and lighted f = c. f = c.   f = 340 m.s -1.64.10 -2 m -1 = 531 Hz 531 Hz l f = 340 m.s -1.0,5.10 -2 m -1 = 68.000 Hz 68.000 Hz Test tube as a Kundt‘s Tube

29. J. W. D ö bereiner (1780-1849) D ö bereiner ‘ s Lighter Jena 1823 Ignition by finely divided platinum powder and a stream of hydrogen directed at it Modelling experiment

30. ©V.O. Low Cost Electrolysis of Water

31. Plus: 2 OH - (aq) → H 2 O + ½O 2 +2e - Minus: 2 H 2 O (l) + 2 e - → H 2 (g) + 2 OH - Redox: H 2 O (l) → H 2 (g) + ½O 2 CO 3 2- + H 2 O → HCO 3 - + OH - ©V.O. Detection of O 2 Detection of H 2 Collection of O 2 Electrolysis

32. Hydrogen-chlorine reaction: H 2 + Cl 2  2 HCl 10 mL chlorine + 10 ml pure hydrogen Flash (LZ 20) KMnO 4 Zn (Grains) HClHCl

33. Low-cost – Generation of C 2 H 2 CaC 2 (s) H2OH2OH2OH2O H2OH2OH2OH2O Ca 2+ (aq) + 2 OH - (aq) Ca 2+ (aq) + 2 OH - (aq) C 2 H 2 storage ++ C 2 H 2 (g)

34. u 20 ml Chlorine u 20 ml Acetylene u Insulation (Electricity wires removed) u 200 ml Erlenmeyer -1 +1 0 0 +1 -1 -1 +1 0 0 +1 -1 C 2 H 2 + Cl 2  2 C + 2 HCl C 2 H 2 + Cl 2  C 2 H 2 Cl 2

35. Low-cost – Generation of O 2 MnO 2 - Tabs H2O2H2O2H2O2H2O2 H2O2H2O2H2O2H2O2 O 2 storage ++ O 2 (g)

36. 0 -1 +1 +4 -2 +1 -2 0 -1 +1 +4 -2 +1 -2 Oxygen: 2½ O 2 + C 2 H 2  2 CO 2 + H 2 O O2O2O2O2 Mixture of 10 ml Oxygen 4 ml Acetylene

37. G. Arcimboldo: Ignis (1566) Kunsthistor. Museum Wien CH 3 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3  CH 3 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 + H 4 H + O-O  2 H 2 O Candle vapour ignition

38. H2H2 Oxygen generation Hydrogen generation O2O2

39. Inverse flames – Small scale version

40. V.O. Microscale Ammonia Fountain NH 3 (g) + H 2 O → NH 4 + + OH ―

41. INSTANT CHEMISTRY Some more examples involving Sulphur dioxide Hydrogen sulphide Carbon monoxide

42. H 2 SO 4 Na 2 SO 3 SO 2 +4 -2 +1 -2 +1 -2 0 +4 -2 +1 -2 +1 -2 0 Sulphur dioxide: SO 2 + 2H 2 S  2H 2 O + 3 S H2SH2SH2SH2S HCl FeS

43. +4 -2 +1 -2 +1 -2 0 +4 -2 +1 -2 +1 -2 0 Sulphur dioxide: SO 2 + 2H 2 S  2H 2 O + 3 S (20 ml) (10 ml)

44. Carbon monoxide as a reducing agent HCOOH → CO + H 2 O H 2 SO 4

45. Desulphurisation plant: +4 -2 +2 +4 -2 +0 +2 +6 -2 +4 -2 SO 2 + CaCO 3 + ½O 2  CaSO 4 + CO 2

46. INSTANT CHEMISTRY Some more examples involving Nitrous Oxide Carbon dioxide Lighter Gas Lighter Fuel Nitrous Oxide Carbon dioxide Lighter Gas Lighter Fuel

47. With the help of a wine bottle opener... Gases and Vapour in the Market place: A great source for N 2 O and CO 2

48. Critical point of Nitrous oxide 36,5°C 72,6bar T P Nitrous Oxide Cotton soaked in Liquid Nitrogen

49. Easy Whip 0,5 l 29 Euro Whipped cream charger: 0,26 Euro Fire extiguishing and similar to gun cotton…. Easy Whip 0,5 l 29 Euro Soda bottle charger: 0,15 Euro

50. Gourmet Whip 0,5 l 65 Euro Sahnekapsel: 0,26 Euro Funktioniert nicht mit Aufsatz der Sodawasser - Bottle !

51. Gourmet Whip 0,5 l 65 Euro Sahnekapsel: 0,26 Euro

52. Bürkle Snowpack: 175 Euro exkl. 30 g/ dry ice per minute 10 l Carbon dioxide bottle with with a special valve: 331 Euro Easy Whip 0,5 l 29 Euro Whipped cream charger: 0,26 Euro

53. 3/2004 LOW COST CANNON for stoichiometric mixtures ©V.O.

54. 1 C 4 H 10 + 13 N 2 O → 4 CO 2 + 5 H 2 O + 13 N 2 (  H R = - 3723 kJ) H 2 + ½ O 2 → H 2 O (  H R = - 242 kJ) Butane, Nitrous oxide and piezo ignition…

55. Reactants Product  H R (kJ) H 2 + 0,5 O 2 → H 2 O - 242 H 2 + Cl 2 → HCl - 185 H 2 + N 2 O → H 2 O + N 2 - 324 NH 3 + 0,75 O 2 → 1,5 H 2 O + 0,5 N 2 - 317 NH 3 + 1,5 N 2 O → 1,5 H 2 O + 2 N 2 - 440 CO + 0,5 O 2 → CO 2 - 283 CO + N 2 O → CO 2 + N 2 - 365 Stoichiometric Mixtures

56. Reactants Product  H R (kJ) CH 4 + 2 O 2 → CO 2 + 2 H 2 O - 802 CH 4 + 4 N 2 O → CO 2 + 2 H 2 O + 4 N 2 -1130 C 2 H 2 + 2,5 O 2 → CO 2 + H 2 O  -1255 C 2 H 2 + 5 N 2 O → 2 CO 2 + H 2 O + 5 N 2  -1666 C 4 H 10 + 6,5 O 2 → 4 CO 2 + 5 H 2 O  -2657 C 4 H 10 + 13 N 2 O → 4 CO 2 + 5 H 2 O + 13 N 2 -3723 Stoichiometric Mixtures

57. ZIPPO boiling range: 113-133 °C (mainly octane) octane: LEL: 0,8 %vol, HEL: 6,5 %vol Vapour pressure of octane: 0,0147 bar 1 C 8 H 18 + 12,5 O 2 → 8 CO 2 + 9 H 2 O v.o. Lighter fuel in a Fuji film can

58. Japanese devices … PbZr x Ti y O 3 lead-titanate-zirconate ceramics

59. ZIPPO-Explosion limit in a Fuji-film can v.o. Volume of the film can = 33 cm 3 Air pressure = 1 bar 78 % N 2 (partial pressure = 0,78 bar) Partial volume = 33cm 3 x 0,78 21 % O 2 (partial pressure = 0,21 bar) partial volume = 33cm 3 x 0,21 = 6,9 cm 3

60. OCTANE Explosion Limit in a Film Can v.o. p (OCTAN) = 0,0147 bar P (AIR) = 1,00 bar p (TOTAL) = 1,0047 bar x: 0,0147 = 33 : 1,0147 x = 0,5 cm 3 0,5 cm 3 C 8 H 18 : 6,9 cm 3 O 2 = 1 : 14 33 : 100 = 0,5 : x x = 1,5 Vol% Vol O 2 = 6,9 cm 3 Vol C 8 H 18 = x cm 3

61. V.O. MANY THANKS TO KAZUKO AND HIROSHI OGINO FOR THE VERY FRIENDLY HOSPITALITY AND HELP ACKNOWLEDGEMENTS Many thanks for your interest