3a.SpecF08#1 - University of Michiganchem125/F08/Lec03F08E2.pdf · · 2008-09-16Au Gold 80 Hg2+...
Transcript of 3a.SpecF08#1 - University of Michiganchem125/F08/Lec03F08E2.pdf · · 2008-09-16Au Gold 80 Hg2+...
Chem.125-126: Sept.17-23
Agenda One hour discussion of E1(Questions, p.48) Two hours of E2; E2 = two session 5 hour lab
Preparation Pre-lab Report (p.63) for E2 completed Discussion Presentation for E1 completed Pre-lab reading and studies for E2 completed
E1:Discussion Preparation
Refer to the discussion grading rubricks, pp. 46-47. Refer to the discussion information, page 233 andposted on CTools. Send presentation to GSI and obtain feedback
E2: Electrons and Solution Color
Session 1: Two Hour Lab Agenda* Complete Part 1(Solution preparation) Complete Part 2 Prepare Part 4 (Solution dilutions) or startPart 3 as indicated by GSI * See Student Information Sheet on Ctools.
Session 2: Three Hour Lab Agenda Complete Parts 3, 4, and 5
E2: Electrons and Solution Color
Is salt solution color predictable based on:• the position of the metal ion’s element in the
periodic table?• the metal ion’s electron configuration (Fig. 3, p. 223)?• the metal ion’s ionic radius (Ionic Sizes, p. 255)?• Its absorption and transmission of visible light?
Goals: See discussion questions (p.73)
Part 1. Preparation and Color of Solutions
1H+
Hydrogen IIIA IVA VA
3Li+
Lithium
4Be
Beryllium
1 1Na+
Sodium
1 2Mg2+
Magnesium IIIB IVB VB VIB VIIB VIIIB ! VIIIB IB IIB
1 3Al3+
Aluminum
1 9K+
Potassium
2 0Ca2+Calcium
2 1Sc
Scandium
2 2Ti
Titanium
2 3V
Vanadium
2 4Cr3+
Chromium
2 5Mn
Manganese
2 6Fe3+Iron
2 7Co2+Cobalt
2 8Ni2+Nickel
2 9Cu2+Copper
3 0Zn2+Zinc
3 1GaGalium
3 2Ge
Germanium
3 7Rb
Rubidium
3 8Sr2+
Strontium
3 9YYitrium
4 0Zr
Zircon-ium
4 1NbNiobium
4 2Mo
Molyb-denum
4 3Tc
Technetium
4 4Ru
Ruthenium
4 5Rh
Rhodium
4 6Pd
Palladium
4 7Ag+Silver
4 8Cd2+
Cadmium
4 9InIridium
5 0
Sn2+
Tin
5 1Sb
Antimony
5 5Cs
Cesium
5 6Ba2+Barium
5 7La*
Lanthanum
7 2Hf
Hafnium
7 3TaTantalum
7 4W
Tungsten
7 5Re
Rhenium
7 6Os
Osmium
7 7IrIridium
7 8PtPlatinum
7 9AuGold
8 0Hg2+
Mercury
8 1TlThallium
8 2
Pb2+Lead
8 3BiBismuth
Teams prepare solutions with different metal ionsRecord the color of solutions.
Solution Color Solutions with ions of the same metal element withdifferent ion charges may have different colors.
DEMO: V2+ vs. V3+ etc.
1H+
Hydrogen IIIA IVA VA
3Li+
Lithium
4Be
Beryllium
1 1Na+
Sodium
1 2Mg2+
Magnesium IIIB IVB VB VIB VIIB VIIIB ! VIIIB IB IIB
1 3Al3+
Aluminum
1 9K+
Potassium
2 0Ca2+Calcium
2 1Sc
Scandium
2 2Ti
Titanium
2 3V
Vanadium
2 4Cr3+
Chromium
2 5Mn
Manganese
2 6Fe3+Iron
2 7Co2+Cobalt
2 8Ni2+Nickel
2 9Cu2+Copper
3 0Zn2+Zinc
3 1GaGalium
3 2Ge
Germanium
3 7Rb
Rubidium
3 8Sr2+
Strontium
3 9YYitrium
4 0Zr
Zircon-ium
4 1NbNiobium
4 2Mo
Molyb-denum
4 3Tc
Technetium
4 4Ru
Ruthenium
4 5Rh
Rhodium
4 6Pd
Palladium
4 7Ag+Silver
4 8Cd2+
Cadmium
4 9InIridium
5 0Sn2+Tin
5 1Sb
Antimony
Periodic Table with common metal ion charges.
Salt solution preparation
Calibration line
Volumetric flasks
Chem.125/126 Mascot
__________________________________________________________
Moles and the Periodic Table?
?
National Mole Day: October 23. Why?
1
H1.008
3
Li6.940
11
Na22.991
19
K39.100
37
Rb85.48
55
Cs132.91
87
Fr(223)
4
Be9.013
12
Mg24.32
20
Ca40.08
38
Sr87.63
56
Ba137.36
88
Ra226.05
58
Ce140.13
5
B10.82
13
Al26.98
31
Ga69.72
49
In114.82
81
Tl204.39
90
Th232.05
6
C12.011
14
Si28.09
32
Ge72.60
50
Sn118.70
82
Pb207.21
7
N14.008
15
P30.975
33
As74.91
51
Sb121.76
83
Bi208.9
8
O15.999
16
S32.06
34
Se78.96
52
Te127.61
84
Po(209)
9
F19.00
17
Cl35.457
35
Br79.916
53
I126.91
85
At(210)
10
Ne20.183
18
Ar39.944
36
Kr83.80
54
Xe131.30
86
Rn(222)
2
He4.003
21
Sc44.96
22
Ti47.90
23
V50.95
24
Cr52.01
25
Mn54.94
26
Fe55.85
27
Co58.94
28
Ni58.71
29
Cu63.54
30
Zn65.38
39
Y88.92
40
Zr91.22
41
Nb92.91
42
Mo95.95
43
Tc(99)
44
Ru101.1
45
Rh102.9
46
Pd106.4
47
Ag107.88
48
Cd112.41
57†
La138.92
72
Hf178.50
73
Ta180.95
74
W183.86
75
Re186.22
76
Os190.2
77
Ir192.2
78
Pt195.09
79
Au197.0
80
Hg200.61
89††
Ac(227)
104
Rf(261)
105
Ha(262)
106
--(263)
59
Pr140.92
60
Nd144.27
61
Pm(145)
62
Sm150.35
63
Eu152.35
64
Gd157.26
91
Pa(231)
92
U238.07
93
Np(237)
94
Pu(242)
95
Am(243)
96
Cm(245)
65
Tb158.93
97
Bk(249)
66
Dy162.51
67
Ho164.94
68
Er167.2
69
Tm168.94
70
Yb173.04
71
Lu174.99
98
Cf(251)
99
Es(254)
100
Fm(255)
101
Md(256)
102
No(254)
103
Lr(257)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Where are moles represented on the periodic table?
Mole
= mol = 6.02 x 1023 item
= atomic wt (g) = formula wt (g)
1
H1.008
3
Li6.940
11
Na22.991
19
K39.100
37
Rb85.48
55
Cs132.91
87
Fr(223)
4
Be9.013
12
Mg24.32
20
Ca40.08
38
Sr87.63
56
Ba137.36
88
Ra226.05
58
Ce140.13
5
B10.82
13
Al26.98
31
Ga69.72
49
In114.82
81
Tl204.39
90
Th232.05
6
C12.011
14
Si28.09
32
Ge72.60
50
Sn118.70
82
Pb207.21
7
N14.008
15
P30.975
33
As74.91
51
Sb121.76
83
Bi208.9
8
O15.999
16
S32.06
34
Se78.96
52
Te127.61
84
Po(209)
9
F19.00
17
Cl35.457
35
Br79.916
53
I126.91
85
At(210)
10
Ne20.183
18
Ar39.944
36
Kr83.80
54
Xe131.30
86
Rn(222)
2
He4.003
21
Sc44.96
22
Ti47.90
23
V50.95
24
Cr52.01
25
Mn54.94
26
Fe55.85
27
Co58.94
28
Ni58.71
29
Cu63.54
30
Zn65.38
39
Y88.92
40
Zr91.22
41
Nb92.91
42
Mo95.95
43
Tc(99)
44
Ru101.1
45
Rh102.9
46
Pd106.4
47
Ag107.88
48
Cd112.41
57†
La138.92
72
Hf178.50
73
Ta180.95
74
W183.86
75
Re186.22
76
Os190.2
77
Ir192.2
78
Pt195.09
79
Au197.0
80
Hg200.61
89††
Ac(227)
104
Rf(261)
105
Ha(262)
106
--(263)
59
Pr140.92
60
Nd144.27
61
Pm(145)
62
Sm150.35
63
Eu152.35
64
Gd157.26
91
Pa(231)
92
U238.07
93
Np(237)
94
Pu(242)
95
Am(243)
96
Cm(245)
65
Tb158.93
97
Bk(249)
66
Dy162.51
67
Ho164.94
68
Er167.2
69
Tm168.94
70
Yb173.04
71
Lu174.99
98
Cf(251)
99
Es(254)
100
Fm(255)
101
Md(256)
102
No(254)
103
Lr(257)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Mole of H2O = _____grams?
Molar Reflections*
Yesterday I took a drink of water And something strange happened in my head I made an actual connectionWith something that my chemistry teacher saidI could visualize lots and lots of moleculesMovin in the water to and fro…and then I thoughtIf I just drank 18 grams of waterI just drank a
Molar reflections, my mind is running freeMaking connections between the world and chemistryA mole is more than a number, more than just a wordIt’s an amount that’s equal to
*Mike Offutt©2002
6.02 times ten to the twenty third!
mole of H2O!
Moles and Solution Concentration
# M = # Molar Solution
# = moles per 1000 mL of solution or mmoles per mL of solution
Example:2.0 M NaCl contains 2 moles NaCl per 1000 mLor 2 mmoles per mL of solution
Salt solution preparation• Read the reagent label for the salt sample CuSO4• 5 H2O CuSO4
DEMO
= Hydrated copper sulfate
= anhydrous copper sufate
Salt solution preparation• Determine the mass of a mole of the salt CuSO4• 5 H2O
Answer______________________________________
= Hydrated copper sulfate
Salt solution preparation• Determine the mass of salt needed to prepare
100 mL of 0.10 M solutionQ. How many grams of CuSO4·5H2O are needed?
_____________________ grams
DEMO
Salt Solution preparation
Calibration line
Volumetric flasks
•Transfer the weighed sample toa 100 mL Vol flask and add waterto the calibration line
Solution Preparation
Salt solution preparation
Information: FW NaClNa + Cl = FW NaCl22.99 + 35.46 = 58.45 g NaCl
Your teammate adds 1 liter (1000 mL) of water to58.45 g of NaCl to prepare 1.0 M NaCl. Theresulting solution was too dilute ( < 1.0 M ). Why?
Answer:____________________________________________________________________________
Solution dilution
One buretcontains
water
Burets clamped to ring stand
One buretcontains thesolution tobe diluted
Solution Dilution
Add H2O
Solution Diluted solution
• Initial moles or mmoles = Final moles or mmoles
Dilution of Solutions
If V= milliliters: M x V = mmol x mL = mmol
mL
Initial mol or mmol = Final mol or mmol M1V1 = M2V2
If V= liters: M x V = mol x L = mol L
Solution Dilution
0.10 M x 10 mL →
+ 10 mL H2O
initial mmoles = final mmoles
Add H2O
1 mmol = 1 mmol
.05 M x 20 mL
Q. What volume of 0.10 M Ni(NO3)2 do you need toprepare 20.0 mL of 0.07 M Ni(NO3)2?
__________________________
M1V1 = M2V2
Q. What volume of H2O do you add to_____ mL of 0.10 M Ni(NO3)2?
_____ mL Ni(NO3)2
_____ mL H2O
Solution Delivery
Fill the buret and tip Record the initial volume
Solution Delivery
Open the stopcock todeliver the solution intothe flask.
Record the final volume;Calculate and record thedelivered solution volume
Q. What volume of 0.20 M Ni(NO3)2 and water do youuse to prepare 10 mL of 0.16 M Ni(NO3)2?
______________________
M1V1 = M2V2
_________ mL 0.20 M Ni(NO3)2+ ______ mL H2O
Light source Diffractiongrating
Samplesolution
Detector
Use a spectrophotometer to examine the relationshipbetween solution color and absorption andtransmission of visible light.
Parts 2 and 3: Electrons and Solution Color
Spectrophotometer
• Record visible wavelength colors (Part 2)
Spectrophotometer
• Record sample absorbance values across thevisible spectrum wavelengths (Part 3).
A plot of absorbance versus wavelength
Absorption Spectrum
Absorbance λmax
Light Absorbance vs. Transmission
0% 10% T 100%
∞ 2 1 A 0
• Absorbance values have no unitsAbs = 1 10% light transmitted
Abs = 2 1% light transmitted
ABSORBANCE = -LOG TRANSMITTANCE
Q. Identify the wavelength of transmission max inthe absorption spectrum below.
Absorption Spectrum
Q. What factor is responsible for changes inabsorbance values?
Absorption Spectrum
Answer.______________________
Beer-Lambert Law A λ = ε c l
absorptivity factor • concentration • path length
Absorbance at λ =
• Concentration and path length are held constantwhile taking the sample’s spectrum (Part 3)
…. To be continued next pre-lab lecture