„ Instant Chemistry“ Viktor Obendrauf (Graz, Austria) viktor@obendrauf.com TEACHING CHEMISTRY...

„„Instant Chemistry“Instant Chemistry“

Viktor Obendrauf (Graz, Austria)Viktor Obendrauf (Graz, Austria)

viktor@obendrauf.comviktor@obendrauf.com

TEACHING CHEMISTRY WITH TEACHING CHEMISTRY WITH SMALL SCALE AND MICROSCALE SMALL SCALE AND MICROSCALE

GAS REACTIONS INCLUDING GAS REACTIONS INCLUDING EXPLOSIONSEXPLOSIONS

International Christian University, TokyoAugust 16 -18 2007

Chemical Society of Japan, TokyoJapan ICU Foundation (JICUF)

V.O.

• are as safe as possible for are as safe as possible for the teacher and the the teacher and the studentsstudents

• are are time-savingtime-saving (preparation, (preparation, performing, clean up) performing, clean up)

• are non-polluting to the are non-polluting to the environment (reduction environment (reduction of waste)of waste)

• are as safe as possible for are as safe as possible for the teacher and the the teacher and the studentsstudents

• are are time-savingtime-saving (preparation, (preparation, performing, clean up) performing, clean up)

• are non-polluting to the are non-polluting to the environment (reduction environment (reduction of waste)of waste)

V.O.

• are are cost-savingcost-saving (materials, (materials, chemicals)chemicals)

• can be referred to the every can be referred to the every day life day life

• can be used to illustrate can be used to illustrate chemical theory chemical theory

• are are cost-savingcost-saving (materials, (materials, chemicals)chemicals)

• can be referred to the every can be referred to the every day life day life

• can be used to illustrate can be used to illustrate chemical theory chemical theory

V.O.

• Is it really necessary to have a fume Is it really necessary to have a fume hood for hazardous gases even hood for hazardous gases even involving very small amounts of involving very small amounts of substances?substances?

• Is it really necessary to have a fume Is it really necessary to have a fume hood for hazardous gases even hood for hazardous gases even involving very small amounts of involving very small amounts of substances?substances?

Oh, so many fixing stands!But what‘s about the reaction?

V.O.

• Is it really necessary that chemical Is it really necessary that chemical demonstrations must be performed demonstrations must be performed at the teacher‘s table exclusively?at the teacher‘s table exclusively?

• Is it really necessary that chemical Is it really necessary that chemical demonstrations must be performed demonstrations must be performed at the teacher‘s table exclusively?at the teacher‘s table exclusively?

What‘s about the safety shield?

V.O.

• Is it possible to use the same material Is it possible to use the same material with the same size for chemical with the same size for chemical demonstrations and for student‘s demonstrations and for student‘s activities?activities?

• Do we have hands-on experiments Do we have hands-on experiments only for physics teaching? only for physics teaching?

• Is it possible to use the same material Is it possible to use the same material with the same size for chemical with the same size for chemical demonstrations and for student‘s demonstrations and for student‘s activities?activities?

• Do we have hands-on experiments Do we have hands-on experiments only for physics teaching? only for physics teaching?

What‘s about the safety shield?

V.O.

Would it be convenient to change Would it be convenient to change demonstrations to microscale to demonstrations to microscale to perform gas experiments closer perform gas experiments closer to the students?to the students?

Would it be convenient to change Would it be convenient to change demonstrations to microscale to demonstrations to microscale to perform gas experiments closer perform gas experiments closer to the students?to the students?

Oh, so many fixing stands!But what‘s about the reaction?

V.O.

• Is it possible to use a portable Is it possible to use a portable apparatus which apparatus which needs no fixing stands?needs no fixing stands?

• Is it possible to use a portable Is it possible to use a portable apparatus which apparatus which needs no fixing stands?needs no fixing stands?

Oh, so many fixing stands!But what‘s about the reaction?

Select your 2 mostSelect your 2 mostfavourite wishesfavourite wishes

in this list ofin this list of5 wishes5 wishes

What do Chemistry teachers really want?What do Chemistry teachers really want?((Results of anResults of an inquiry among 2000 Chemistry teachers)inquiry among 2000 Chemistry teachers)

Percent (response from 632 colleagues in autumn 1999)

54,6

43,2

37,4

36,3

22,3

0 20 40 60

More time fordiscussing newtopicsMore money topurchasematerialMore textbookstesteddidacticallyMore time forrepeating thecontextsMore recipes fortime-savingHands-on

V.O.

V.O.

Chemical experiments are an

Chemical experiments are an

essential part of chemical education.

essential part of chemical education.

Could it be, that a very

Could it be, that a very time-consumingtime-consuming

experiment is mainly food for the playing

experiment is mainly food for the playing

instinct of the teacher

instinct of the teacher ??

Could a Could a time-consuming

time-consuming experiment be rather

experiment be rather

boring and useless for improving the

boring and useless for improving the

knowledge of the students

knowledge of the students ??

Is there enough Is there enough timetime to teach, to discuss and to

to teach, to discuss and to

repeat the chemical background and contexts

repeat the chemical background and contexts ??

INSTANT CHEMISTRYINSTANT CHEMISTRYTwo Criteria for Chemical Hands-on:Two Criteria for Chemical Hands-on:

•Time-savingTime-saving: The experiment should : The experiment should be done within a couple of minutes be done within a couple of minutes including clean up.including clean up.

•Cost-savingCost-saving: The experiment should : The experiment should involve familiar and cheap every day involve familiar and cheap every day common material.common material.

INSTANT CHEMISTRYINSTANT CHEMISTRY

Examples involvingExamples involving

Chlorine Hydrogen, Chlorine Hydrogen, Acetylene, Oxygen, AmmoniaAcetylene, Oxygen, Ammonia

Well known problems with Well known problems with

classical generation of gasesclassical generation of gases

0 0 +1 -10 0 +1 -1 Na + ½ ClNa + ½ Cl22 NaCl NaCl

Large Scale ?Large Scale ?

Complicated arrangements Complicated arrangements too far away from the too far away from the

studentsstudents

Time-consumingTime-consuming (preparation, clean up) (preparation, clean up)

Expensive materialExpensive material

Great demand of chemicals because Great demand of chemicals because of big flasks containing airof big flasks containing air

Noisy and bad positioned fume hoodsNoisy and bad positioned fume hoodsGeneration of wasteGeneration of waste

0 0 +1 -10 0 +1 -1 Chlorine: ½ ClChlorine: ½ Cl22 + Na + Na NaCl NaCl

What about going Smallscale

What about going Smallscale

or Microscale without

or Microscale without

changing the system?

changing the system?

SmallscaleSmallscale

or Microscale ?or Microscale ?

0 0 +1 -10 0 +1 -1 Chlorine: ½ ClChlorine: ½ Cl22 + Na + Na NaCl NaCl

Danger and Disadvantages:Danger and Disadvantages:

Complicated arrangementsComplicated arrangements

Fixed at the teacher‘s tableFixed at the teacher‘s table

Rather time-consuming Rather time-consuming (preparation, clean up) (preparation, clean up)

Expensive materialExpensive material

• 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 Low Cost Generator for various Gases for various Gases

V.O. ©

Rubber stopper Rubber stopper Verneret 18DVerneret 18D

Test tube Test tube Fiolax 16/160 mmFiolax 16/160 mm

2 Needles 1,2/40 mm2 Needles 1,2/40 mm

2ml syringe 2ml syringe (plunger hard to move)(plunger hard to move)

20ml syringe ONCE 20ml syringe ONCE (plunger greased with (plunger greased with special silicon oil)special silicon oil)

Cut tips

V.O. ©

Gas kit I V.O. © Gas kit II V.O. ©

Low-cost – Generation of Cl2

KMnOKMnO44 (s) (s)

HCl HCl conc.conc.HCl HCl conc.conc.

Mn Mn 2+ 2+ (aq)(aq)

ClCl22-storage-storage++

ClCl2 2 (g)(g)

V.O.

V.O.

0 0 +1 -10 0 +1 -1 Sodium chloride ½ ClSodium chloride ½ Cl22 + Na + Na NaCl NaCl

Reaction productReaction product+ 1 drop of water+ 1 drop of wateron a microscope slideon a microscope slidewater evaporated,water evaporated,stereo microscope stereo microscope 40 times +FLEXCAM40 times +FLEXCAM

Low-cost – Generation of H2

Zn (s)Zn (s)

HCl HCl conc.conc.HCl HCl conc.conc.

Zn Zn 2+ 2+ (aq)(aq) + 2 Cl+ 2 Cl- - (aq)(aq)

HH22-storage-storage++

HH2 2 (g)(g)

• Test tube Fiolax 16/160Test tube Fiolax 16/160• 15 ml Hydrogen15 ml Hydrogen• Procedure:Procedure:

15 ml Hydrogen are 15 ml Hydrogen are

injected into the test tubeinjected into the test tube

and lightedand lighted

• f = c . f = c .

f = 340 m.sf = 340 m.s-1 -1 .64.10.64.10-2 -2 mm-1-1==

531 Hz531 Hz f = 340 m.sf = 340 m.s-1 -1 .0,5.10.0,5.10-2 -2 mm-1 -1 ==

68.000 Hz68.000 Hz

Test tube as a Kundt‘s Test tube as a Kundt‘s TubeTube

J. W. Döbereiner (1780-1849)J. W. Döbereiner (1780-1849)Döbereiner‘s Lighter Jena 1823

Ignition by finely divided platinum powder and a stream of hydrogen directed at it

Modelling experimentModelling experiment

©V.O.

Low Cost Electrolysis of WaterLow Cost Electrolysis of Water

Low Cost Electrolysis of WaterLow Cost Electrolysis of Water

Plus: Plus: 2 OH2 OH-- (aq) (aq) →→ H H22O + ½OO + ½O2 2 +2e+2e--

Minus:Minus:2 H2 H22O (l) + 2 eO (l) + 2 e-- →→ H H22 (g) + 2 OH (g) + 2 OH--

Redox: HRedox: H22O (l) O (l) →→ H H22 (g) + ½O (g) + ½O2 2

CO32- + H2O →

HCO3- + OH-

©V.O.

Detection of O2

Detection of H2

Collection of O2

Electrolysis

Hydrogen-chlorine reaction: HHydrogen-chlorine reaction: H22 + Cl + Cl22 2 HCl 2 HCl

10 mL chlorine

+ 10 ml pure hydrogen

Flash (LZ 20)

KMnOKMnO44 Zn (Grains)Zn (Grains)

HClHCl HClHCl

Low-cost – Generation of C2H2

CaCCaC22 (s) (s)

HH22OOHH22OO

CaCa2+ 2+ (aq)(aq) + 2 OH+ 2 OH- - (aq)(aq)

CC22HH22

storagestorage

++

CC22HH2 2 (g)(g)

20 ml Chlorine20 ml Chlorine 20 ml Acetylene20 ml Acetylene Insulation Insulation

(Electricity (Electricity wires removed)wires removed)

200 ml 200 ml ErlenmeyerErlenmeyer

-1 +1 0 0 +1 -1-1 +1 0 0 +1 -1

CC22HH22 + Cl + Cl22 2 C + 2 HCl 2 C + 2 HCl

CC22HH22 + Cl + Cl22 C C22HH22ClCl22

Low-cost – Generation of O2

MnOMnO22--

TabsTabs

HH22OO22HH22OO22

OO22

storagestorage

++

OO2 2 (g)(g)

0 -1 +1 +4 -2 +1 -20 -1 +1 +4 -2 +1 -2 Oxygen: 2½ OOxygen: 2½ O22 + C + C22HH2 2 2 CO 2 CO22 + H + H22OO

OO22 Mixture of

10 ml Oxygen

4 ml Acetylene

G. Arcimboldo: Ignis (1566)Kunsthistor. Museum Wien

CHCH33-CH-CH22-CH-CH22-CH-CH22-CH-CH22-CH-CH22-CH-CH22-CH-CH3 3 CHCH33-CH-CH22-CH-CH22-CH-CH22-CH-CH22-CH-CH22-CH-CH22-CH-CH22• + H•• + H•

4 H• + •O-O• 4 H• + •O-O• 2 H 2 H22OO

Candle vapour ignition

H2

Oxygen generation

Hydrogen generation

O2

Inverse flames – Small scale versionInverse flames – Small scale version

V.O.

Microscale Microscale Ammonia Ammonia FountainFountain

NHNH33(g) + H(g) + H22O O →→ NHNH44++ + OH + OH――

INSTANT CHEMISTRYINSTANT CHEMISTRY

Some more examples involvingSome more examples involving

Sulphur dioxide Sulphur dioxide Hydrogen sulphide Hydrogen sulphide

Carbon monoxide Carbon monoxide

HH 22SOSO 44

NaNa 22SOSO 33

SOSO22

+4 -2 +1 -2 +1 -2 0+4 -2 +1 -2 +1 -2 0

Sulphur dioxide: SOSulphur dioxide: SO22 + 2H + 2H22S S 2H 2H22O + 3 SO + 3 S

HH22SSHCl HCl

FeSFeS

+4 -2 +1 -2 +1 -2 0+4 -2 +1 -2 +1 -2 0

Sulphur dioxide: SOSulphur dioxide: SO22 + 2H + 2H22S S 2H 2H22O + 3 SO + 3 S

(20 ml)(20 ml)(10 ml)(10 ml)

Carbon Carbon monoxide as a monoxide as a reducing agentreducing agent

HCOOH → CO + H2OH2SO4

Desulphurisation plant:Desulphurisation plant:

+4 -2 +2 +4 -2 +0 +2 +6 -2 +4 -2+4 -2 +2 +4 -2 +0 +2 +6 -2 +4 -2

SOSO22 + CaCO + CaCO33 + ½O + ½O22 CaSO CaSO4 4 + CO+ CO22

INSTANT CHEMISTRYINSTANT CHEMISTRY

Some more examples involvingSome more examples involving

Nitrous Oxide Nitrous Oxide Carbon dioxide Carbon dioxide

Lighter Gas Lighter Gas Lighter FuelLighter Fuel

With the help of a With the help of a wine bottle opener...wine bottle opener...

Gases and Vapour in the Market place: A great source for N2O and CO2

Gases and Vapour in the Market place: A great source for N2O and CO2

Critical point of Nitrous oxideCritical point of Nitrous oxide

36,5°C

72,6bar

TT

72,6bar

PP

Nitrous

Oxide

Cotton soakedin LiquidNitrogen

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

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

Funktioniert nicht mit Aufsatz der Sodawasser- Bottle !

Funktioniert nicht mit Aufsatz der Sodawasser- Bottle !

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

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

3/2004

LOW COST CANNON for stoichiometric mixtures

©V.O.

1

CC44HH1010 + 13 N + 13 N22O O → → 4 CO4 CO2 2 ++ 5 H5 H22O + 13 NO + 13 N22

((HHRR = - 3723 kJ) = - 3723 kJ)

HH22 + ½ O + ½ O22 →→ H H22O (O (HHRR = - 242 kJ) = - 242 kJ)

Butane, Nitrous oxide and piezo ignition…

Reactants Product Reactants Product HHRR (kJ) (kJ)

HH22 + 0,5 O + 0,5 O22 →→ HH22OO - 242- 242

HH2 2 + Cl+ Cl22 →→ HCl HCl - 185- 185

HH2 2 + N+ N22O O →→ HH22O + NO + N22 - 324- 324

NHNH33+ 0,75 O+ 0,75 O22 →→ 1,5 H1,5 H22O + 0,5 NO + 0,5 N22 - 317- 317

NHNH33+ 1,5 N+ 1,5 N22O O →→ 1,5 H1,5 H22O + 2 NO + 2 N22 - 440- 440

CO + 0,5 OCO + 0,5 O22 →→ COCO22 - 283- 283

CO + NCO + N22OO →→ COCO2 2 + N+ N22 - 365- 365

Stoichiometric Mixtures

Reactants Reactants Product Product HHRR (kJ) (kJ)

CHCH44 + 2 O + 2 O22 →→ COCO22 ++ 2 H2 H22OO - 802 - 802

CHCH4 4 + 4 N+ 4 N22O O →→ COCO2 2 ++ 2 H2 H22O + 4 NO + 4 N22 -1130 -1130

CC22HH2 2 + 2,5 O+ 2,5 O22 →→ COCO2 2 + H+ H22O O -1255 -1255

CC22HH2 2 + 5 N+ 5 N22O O →→ 2 CO2 CO2 2 + H+ H22O + 5 NO + 5 N22 -1666-1666

CC44HH10 10 + 6,5 O+ 6,5 O22 →→ 4 CO4 CO2 2 + 5 H+ 5 H22O O -2657-2657

CC44HH10 10 + 13 N+ 13 N22O O →→ 4 CO4 CO2 2 + 5 H+ 5 H22O + 13 NO + 13 N22 -3723 -3723

Stoichiometric Mixtures

ZIPPO boiling range: 113-133 °C (mainly octane)

octane: LEL: 0,8 %vol, HEL: 6,5 %vol

Vapour pressure of octane: 0,0147 bar

11 C C88HH1818 + 12,5 O + 12,5 O22

→ → 8 CO8 CO2 2 + 9 H + 9 H22OO

v.o.

Lighter fuel in a Fuji film can

Japanese devices…

PbZrxTiyO3

lead-titanate-zirconateceramics

ZIPPO-Explosion limit in a Fuji-film can

v.o.

Volume of the film can = 33 cmVolume of the film can = 33 cm33

Air pressure = 1 barAir pressure = 1 bar

78 % N78 % N22

(partial pressure = 0,78 bar)(partial pressure = 0,78 bar)Partial volume = 33cmPartial volume = 33cm33 x 0,78 x 0,78

21 % O21 % O22

(partial pressure = 0,21 bar)(partial pressure = 0,21 bar)partial volume = 33cmpartial volume = 33cm33 x 0,21 = x 0,21 =

6,9 cm6,9 cm33

OCTANE Explosion Limit in a Film Can

v.o.

pp(OCTAN)(OCTAN) = 0,0147 bar = 0,0147 barPP(AIR)(AIR) = 1,00 bar = 1,00 barpp(TOTAL)(TOTAL) = 1,0047 bar = 1,0047 bar

x: 0,0147 = 33 : 1,0147 x: 0,0147 = 33 : 1,0147 x =x = 0,5 cm0,5 cm33 0,5 cm0,5 cm33 CC88HH1818 : 6,9 cm: 6,9 cm3 3 OO22 = 1 : 14 = 1 : 14

33 : 100 = 0,5 : x 33 : 100 = 0,5 : x x = 1,5 Vol%x = 1,5 Vol%

Vol O2 = 6,9 cm3

Vol C8H18 = x cm3

V.O.

MANY THANKS TOMANY THANKS TO KAZUKO AND HIROSHI OGINOKAZUKO AND HIROSHI OGINO

FOR THE VERY FRIENDLY HOSPITALITY AND FOR THE VERY FRIENDLY HOSPITALITY AND HELPHELP

ACKNOWLEDGEMENTSACKNOWLEDGEMENTS

Many thanks Many thanks for your for your

interestinterest