development ofdevelopment of microscale …spec/microscalechemmeeting.pdfdepartment of applied...
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The 92th Chemical Society of Japan Spring Meeting, Mar. 25, 2012, Tokyo
大学教育に適用可能な物理化学実験のマイクロスケ ル化 の取り組み(1)マイクロスケール化への取り組み(1)
Development of microscale experimentsDevelopment of microscale experiments in physical chemistry for chemical education
for ndergrad ates part Ifor undergraduates - part I
Shota Kuwahara, Akira Takeda, Tomorou Miyahara, Naomi Tsuchiya, Kenji Katayama
Department of Applied Chemistry, Chuo University
Outline
1. Introduction
1 1 Mi l i t f i it1-1. Microscale experiment for university
1-2. Typical curriculum of Physical Chemistry
1-3. Theme of microscale experiments
2. Development of microscale experiment
2-1. The gas lawg
2-2. Liquid-liquid equilibria of binary systems
3. Conclusion
2010/ 6/14 @ Chuo Univ.
IntroductionMicroscale experiment
→ Experiment using a few reagent or small instrument
Advantage
・Less experimental risksp
・Reduce waste
・Lower costs for chemicals d i
・Save time for preparation
・Shorter experimental times
and equipment
・Shorter experimental times
・More time for evaluation
・Smaller working space
o e e o e a ua oand discussion about result
IntroductionMicroscale experiment
→ Experiment using a few reagent or small instrument
Advantage
・Less experimental risks For universityp
・Reduce waste
・Lower costs for chemicals d i
・Budget: 10 times larger than high school
・Mechanical equipments can be used.
・Save time for preparation
・Shorter experimental times
and equipment Ex. Pipette, Magnetic Stirrer, Heater…
・Analytical equipments can be used.Ex. UV/Vis, IR, Chromatography…・Shorter experimental times
・More time for evaluation
・Smaller working space ・Mathematical calculations can be made by a computer.
, , g p y
St d t h i t t i h i to e e o e a ua oand discussion about result
I thi k h d l d i l i t i
・Students have interests in chemistry.
In this work, we have developed microscale experiments in physical chemistry for chemical education of undergraduates.
Scheme of development of microscale experiments
Pl iSelection of theme
Planning&
Development
Check Trial experimentVerification Trial experimentVerification
Typical curriculum of Physical Chemistry
1. Property of gas
2. Enthalpy
3 Entropy3. Entropy
4. Mixture of chemicals
5. Phase diagram
6. Equilibriumq
7. Electrochemistry
Typical curriculum of Physical Chemistry
1. Property of gas The work of gas
2. Enthalpy
3 Entropy
Calorimetry
3. Entropy
4. Mixture of chemicals
5. Phase diagram
6. Equilibrium
Liquid-liquid equilibria of binary systemsq
7. Electrochemistry Electromotive force of electrochemical cellselectrochemical cells
Z. Szafran, R. M. Pike, J. C. Foster, “Microscale General Chemistry Laboratory”, Wiley.東海林恵子、荻野和子, 化学と教育 49 712 (2001) .
Typical curriculum of Physical Chemistry
1. Property of gas The work of gas
2. Enthalpy
3 Entropy
Calorimetry
3. Entropy
4. Mixture of chemicals
5. Phase diagram
6. Equilibrium
Liquid-liquid equilibria of binary systemsq
7. Electrochemistry Electromotive force of electrochemical cellselectrochemical cells
Z. Szafran, R. M. Pike, J. C. Foster, “Microscale General Chemistry Laboratory”, Wiley.東海林恵子、荻野和子, 化学と教育 49 712 (2001) .
Microscale experiment 1 - The work of gasPoint
1. Experience the Boyle’s law.
2. Understand the difference between reversible and irreversible compression.irreversible compression.
Physical Chemistry Atkins sixth editionPhysical Chemistry, Atkins, sixth edition
Microscale experiment 1 - The work of gasPoint
1. Experience the Boyle’s law.Microscale experiment
2. Understand the difference between reversible and irreversible compression.
Force gaugeirreversible compression.
AdAdvantage
1. Simple experimental setup
2. Easy handling
3. Directly and easily i h
Syringe
measuring the pressureZ stage
Definition of the work of gas – the Boyle’s law
F
Pdz
P
CompressedVV
PdVAdzPdzFdwin =×=×=
∫=2
1
V
Vin PdVw
Experimental – reversible vs irreversible compression
Reversible ⇒ Press the syringeReversible ⇒ Press the syringe slowly
Irreversible ⇒ Press the syringe quickly
Analysis of obtained results by using PC and software
Making & analysis of pressure (p) – volume (V) curve
Work Theoretical Reversible Irreversible
W[J] 422 486 537W[J] 422 486 537
Microscale experiment 2 – Binary phase diagramPoint
1. Understand how to make d bi h diand use binary phase diagram.
2. Understand the phase rule and liquid liquid equilibriaand liquid-liquid equilibria.
Microscale experiment 2 – Binary phase diagramPoint
1. Understand how to make d bi h di
Microscale experiment
Thermometerand use binary phase diagram.
2. Understand the phase rule and liquid liquid equilibria Screw bottle x 6and liquid-liquid equilibria.
Ad
Screw bottle x 6(1 mL)
Advantage
1. Smaller working space
2. Enough time to do further experiments (Ex. Lever rule)
3 E t
Hot magnetic stirrer
3. Easy to compare mass fraction with liquid mutual solubility
Liquid-liquid binary phase diagram Methanol/Cyclohexane system– Methanol/Cyclohexane system –
Heating
Cooling
P = 2 P = 1Two phase system Single phase
Record the temperature of cloud points
Liquid-liquid binary phase diagram Methanol/Cyclohexane system– Methanol/Cyclohexane system –
The error of the temperature is within 1 OCThe error of the temperature is within 1 C.
H. Matsuda et al., J. Chem. Eng. Data 43 184 (2003).
Further experiment – the lever rule
a
bb
The lever rule
(nA, nB:the mass of each phase)bBaA lnln ×=×
Further experiment – the lever rule
a
bb
Mass fraction [-] Methanol mass fraction [-]
Phase a Phase bThe lever rule 0.23 0.77
The lever rule 0.64Experimental
Experimental
Further experiment – the lever rule
aMass fraction of methanol (a) = ρ(a) x V(a)
V(a)
b
ρ(a) x V(a)
Mass fraction of methanol (b) (b) V(b)
V(b) b= ρ(b) x V(b)
Mass fraction [-] Methanol mass fraction [-]
Phase a Phase bThe lever rule 0.23 0.77
The lever rule 0.64Experimental
Experimental 0.26 0.74
Further experiment – the lever ruleRefractrometer
a0.84
0.86Refractrometer
b0.8
0.82
ve in
dex
b
0.76
0.78
Ref
lact
iv
0.741.34 1.345 1.35 1.355
Mass fraction of methanol [-]
Mass fraction [-] Methanol mass fraction [-]
Phase a Phase bThe lever rule 0.23 0.77
The lever rule 0.64Experimental 0.65
Experimental 0.26 0.74
Rating and comments – from undergraduates –
1 Th l1. The gas laws1. Easy to operate
2 Easy to understand2. Easy to understand
3. The experimental error depends on operators.depends on operators.
2. Binary phase diagram
1. Easy to operate
2. Well understand the phase diagram through the microscaleexperiments
3 Long time (~ 1 h) is required3. Long time (~ 1 h) is required to observe the phase change.
Conclusion
1. We have succeeded in developing the microscaleexperiments in physical chemistry for chemical d ti f d d t t d teducation of undergraduate students.
2. Reversible and irreversible compression of the gas p glaw was confirmed through microscale experiments.
3 Liquid liquid binary phase diagram of3. Liquid-liquid binary phase diagram of methanol/cyclohexane system was successfully made by microscale experiments.by microscale experiments.
4. It was confirmed that the developed microscalei t h d d t di f bj t iexperiments enhanced understanding of subjects in
physical chemistry for undergraduate students.
Web of microscale experimenthttp://www.chem.chuo-u.ac.jp/~spec/microscale_pre.html
1H21H2--09 09 2012/3/252012/3/25
Development of microscale experiments Development of microscale experiments i h i l h i t f h i l d tii h i l h i t f h i l d tiin physical chemistry for chemical educationin physical chemistry for chemical education
for undergraduatesfor undergraduates--partpartⅡⅡ大学教育に適用可能な物理化学実験の大学教育に適用可能な物理化学実験のマイクロスケ ル化への取り組みマイクロスケ ル化への取り組み(2)(2)マイクロスケール化への取り組みマイクロスケール化への取り組み(2)(2)
Naomi TsuchiyaNaomi Tsuchiya, Taeko Yabe, Shota Kuwahara,, Taeko Yabe, Shota Kuwahara,Kenji KatayamaKenji Katayama
Department of Applied Chemistry, Chuo UniversityDepartment of Applied Chemistry, Chuo University
Typical curriculum of Physical Chemistry
1. Property of gas
2. Enthalpy
3 Entropy3. Entropy
4. Mixture of chemicals
5. Phase diagram
6. Equilibriumq
7. Electrochemistry
2
Typical curriculum of Physical Chemistry
1. Property of gas Work of gas
2. Enthalpy
3 Entropy
Calorimetry
3. Entropy
4. Mixture of chemicalsPh di5. Phase diagram
6. Equilibrium
Phase diagram for binary liquid system
q
7. Electrochemistry Electromotive force of electrochemical cellselectrochemical cells
3
Typical curriculum of Physical Chemistry
1. Property of gas Work of gas
2. Enthalpy
3 Entropy
Calorimetry
3. Entropy
4. Mixture of chemicalsPh di5. Phase diagram
6. Equilibrium
Phase diagram for binary liquid system
q
7. Electrochemistry Electromotive force of electrochemical cellselectrochemical cells
4
Calorimetry
To measure neutralization heat by i i id d b d
Conventional
mixing acid and base and dissolution heat by dissolving alkali metal salt to water
SHIMADZU
5
Calorimetry
To measure neutralization heat by i i id d b d
Conventional
mixing acid and base and dissolution heat by dissolving alkali metal salt to water
100 mL
6
Calorimetry
To measure neutralization heat by i i id d b d
Microscale
mixing acid and base and dissolution heat by dissolving alkali metal salt to water 10 mL
12 cm
bottle
Advantage
5 cm15 cm
12 cmAdvantage
A few reagentSmall heat capacity of container A few reagentSmaller working space
Point
To calculate ⊿H by measuring ⊿TZ S f R M Pik J C F t
7
To discuss the correlation between⊿HHyd and ion radius of alkali metal
Z. Szafran, R.M.Pike, J.C.Foster, MICROSCALE GENERAL CHEMISRY LABORATORY, Wiley (1993)
Neutralization of HCl and NaOH
26
28
℃]
24
26
erat
ure[℃
⊿TReaction heat is consumed
for the temperature
22Tem
pe
⊿T for the temperature increase of not only solvent but also container
200 60 120 180 240
Time[s]Time[s]
TCTmCH containerp Δ+Δ=Δ− molkJH /4.66=⊿
lkJH /556⊿8
p molkJH ltheoretica /5.56⊿
Dissolution of alkali metal salt totwater
M+(g)+X-(g)
ΔHHydΔHLTheoretical22
26
℃]
NaI
N Cl
M+(aq)+X-(aq)18
mpe
ratu
re[℃
KI
NaCl
MX(s)
( q) ( q)ΔHSol
Experimental10
14Tem
KCl
0 100 200 300Time[s]
⊿H ⊿H KI KCl NaI NaCl
Hydration enthalpy
⊿Hexperimental18.9kJ/mol17.9kJ/mol7 1kJ/ l
⊿Htheoretical20.3kJ/mol17.2kJ/mol7 5kJ/ l
KIKClN I
KI KCl NaI NaCl
‐630 ‐699 ‐712 ‐785
9
-7.1kJ/mol1.79kJ/mol
-7.5kJ/mol3.9kJ/mol
NaINaCl
Ion radiusBigger Smaller
Electromotive force of electrochemical llcell
To measure electromotive forces of a Daniel cell
Conventional
[ Zn|Zn(NO3)2||Cu(NO3)2|Cu ], changing temperature and concentrations of solutions
10
Electromotive force of electrochemical llcell
To measure electromotive forces of a Daniel cell
Microscale
[ Zn|Zn(NO3)2||Cu(NO3)2|Cu ], changing temperature and concentrations of solutions
Diameter2.2 cmAdvantage
8 cmEasy to compare A few reagent
12.5 cmTo calculate ⊿G,⊿S,⊿H by
Point
ymeasurement of electromotive force of Daniel cellTo confirm the Nernst’s equation
11
To confirm the Nernst s equation by changing the concentration of electrolyte solutions
東海林恵子, 荻野和子, 化学と教育, 49, 712, (2001)
Electromotive force of Daniel cell
G ⎞⎛⊿
Nernst’s equationThermodynamic function of state
nFEG −=⊿ STG
p
−=⎟⎠
⎞⎜⎝
⎛⊿
⊿
STGH ⊿⊿⊿][][ln 2
2
+
+
−=CuZn
nFRTEE ο
y = -0.0142x + 1.34341
e [V
]
y = -0.0098x + 0.9496
1.1
e[V
]
STGH ⊿⊿⊿ += ][CunF
0.9
mot
ive
forc
e
1
mot
ive
forc
e0.7
0.8
Ele
ctro
m
0 8
0.9
Ele
ctro
m0.7
25 30 35 40 45 50Temperature[℃]
0.8-8 -6 -4 -2 0 2 4 6 8
ln[Zn2+]/[Cu2+][-]
molKJS ・⊿ /62740VE 11⊿ lkJG /3212⊿12molkJG /8.190−=⊿
molKJS ・⊿ /6.2740−=molkJH /5.1007−=⊿VE 99.0=⊿
VE ltheoretica 1.1=⊿ molkJG ltheoretica /3.212−=⊿
Rating and commentsf d d tfrom undergraduates
Ease ofoperation
Daniel cell
Easy to understandEasy to operate
2345
operation
ReagentSafety y
Not care for the dangerous reagents because of small
12 volumeSafety
Difficult matters can be d t d i ll
quantityUnderstandingTime required
Calorimetry understood visually Think over because of doing experiments4
5
Ease ofoperation
Calorimetry
doing experiments aloneSusceptible to errors1
234
ReagentvolumeSafety
Susceptible to errors because of small quantity
UnderstandingTime required 13
Conclusion
We could develop microscale experiments according to th i l f h i l h i t f h i lthe curriculum of physical chemistry for chemical education for undergraduatesーThe gas lawsThe gas lawsーCalorimetryーLiquid-liquid equilibria of binary systemsq q q y y-Electromotive force of electrochemical cells
Microscale experiments can be easily introduced toMicroscale experiments can be easily introduced to students and would help understanding theories
14Web of microscale experimenthttp://www.chem.chuo-u.ac.jp/~spec/microscale_pre.html