Concept Presentation
Tuesday, July 13, 2010
C. Burt
Presentation Outline
 Introduction
 Curriculum Expectations
 Student Demographic
 Instructional Approaches
 Misconceptions
 Textbook Issues
 Assessment & Evaluation
 References
Qualitative Analysis
http://jchemed.chem.wisc.edu/JCESoft/CCA/
CCA3/STILLS/FEZNSUL/FEZNSULF/64JPG
48/6.JPG
http://edu.glogster.com/media/1/9/42/67
/9426718.jpg
http://www.gettyimages.ca/detail/2004
48588-001/Riser?language=enUS&location=CAN
Curriculum Expectations
B2.3 investigate precipitation reactions and flame tests, using
qualitative analysis instruments, equipment and techniques
[PR, AI]
B2.4 conduct qualitative analysis of an unknown sample, using
a flow chart and experimental procedures, including flame
tests and precipitation reactions to determine the presence of
metal ions [PR, AI]
B2.5 identify an unknown gas sample by observing its
emission spectrum and comparing it to the spectra of known
gases [PR, AI]
What does it look like?
http://gabudjr.files.wordpress.com/2009/11/flammes_colorees_petit.jpg
http://staff.norman.k12.ok.us/~cyohn/in
dex_files/ddlab_files/image001.jpg
What does it look like?
http://www.physics.umd.edu/courses/Phys401/bedaque07/discrete_spectra.jpg
Who are the Students?
SNC2D
Grade 10, Academic
SCH4C
Grade 12, College
SNC2P
Grade 10, Applied
Why is it important?
Forensics
 identification of unknown materials
 association of unknowns to potential sources
Fireworks
 production of colourful pyrotechnic displays for entertainment
purposes
Food/Water Quality Analysis
 contamination recognition
 toxicity testing
Astronomy
 indirect identification of atoms on celestial objects
Course Context
 Matter & Qualitative Analysis = first unit of SCH4C
 review the periodic table, symbols and atomic theories
 foundation for the remainder of the course (Shamai
and Stavy, 1986)
 develop good lab skills
Proposed Sequence – Lesson #1
1. Review physical properties of matter
2. Relate unique chemical structure to qualitative
properties

examine solids and solutions
3. Introduce the flame test as a qualitative technique



compare solution colours to flame colours
demonstrate technique for lab
disclose what they need to show for evaluation
Misconceptions
1. impossible to differentiate between white powders
2. colour of solid and solution is identical or similar to
that of the flame test colour
Textbook Tables
Solution Colour
Ions
Symbol
Colour
chromium (II)
copper (II)
Cr2+
blue
Cu2+
chromium (III)
copper (I)
iron (II)
nickel (II)
Cr3+
Cu+
Fe2+
Ni2+
green
iron (III)
Fe3+
pale yellow
cobalt (II)
manganese (II)
Co2+
pink
Flame Colour
Ion
Symbol
Colour
lithium
Li+
red
sodium
Na+
yellow
potassium
K+
violet
cesium
Cs+
violet
calcium
Ca2+
red
strontium
Sr2+
red
barium
Ba2+
yellowishgreen
copper
Cu2+
bluishgreen
boron
B2+
green
lead
Pb2+
bluishwhite
Mn2+
Chemistry 11, McGraw-Hill Text
Remake the Tables!
 have the students make the tables
 encourage good lab skills
 allow them to test multiple times
Ions
Symbol
Colour
chromium (II)
copper (II)
Cr2+
Cu2+
blue
chromium (III)
copper (I)
iron (II)
nickel (II)
Cr3+
Cu+
Fe2+
Ni2+
green
iron (III)
Fe3+
pale yellow
cobalt (II)
manganese (II)
Co2+
Mn2+
pink
http://www.cwcompliance.com/whmis_flammable.jpg
Proposed Sequence – Lesson #2
1. Pre-lab preparation
2. Conduct lab

students generate their own tables
3. Practice assessment



students use their generated tables with unknown
samples
can self-assess whether their tables were poor or helpful
test household solutions
Proposed Sequence – Lesson #3
1. Introduce precipitate formation as a qualitative
technique

demo #2
Proposed Sequence – Lesson #3
1. Introduce precipitate formation as a qualitative
technique

demo #2
2. Review terms (soluble, insoluble, aqueous)
3. Demonstrate how to read solubility tables
4. Experiment with various dropper bottles and spot plates

allow students time to see reactions and associate
solubility table
Textbook Table – Example #1
http://castlelearning.com/review/reference/chem%20table%20f.gif
Textbook Table – Example #2
http://www.professormeyer.com/images/solubility%20chart.jpg
Textbook Table – Example #3
Anions
Cations
High
Solubility
(aq)
≥ 0.1 mol/L
(at SATP)
ClBrI-
S2-
OH-
SO42-
CO32PO43SO32-
C2H3O2-
NO3-
most
Group 1
Group 2
NH4+
Group
1
NH4+
Sr2+
Ba2+
Tl+
most
Group 1
NH4+
most
all
All Group 1 compounds, including acids, and all ammonium
(NH4+) compounds are assumed to have high solubility in water.
Low
solubility
(s)
< 0.1 mol/L
(at SATP)
Ag+
Pb2+
Tl+
Hg22+
(Hg+)
Cu+
most
most
Ag+
Pb2+
Ca2+
Ba2+
Sr2+
Ra2+
most
Ag+
none
Solubility Song
Evaluation
1. Standard pen & paper
test (I)
2. Practical test (K / I)
3. Make a fire log which
burns in a specific
colour sequence. (A)
4. Identification of ions in
drinking water (I)
http://image09.webshots.com/9/8/54/94/111785494sGJSS
V_fs.jpg
References
1. Ministry Documents – Grade 11 and 12 Science
2. Shamai, R. and Stavy, R., Teaching an Introductory
Course in Qualitative Analysis in Order to Enhance
Learning General Chemistry, J. Chem. Educ., 1986, 63
(8), p 707
3. Chemistry 12 College Preparation, Nelson Text, 2004
4. Chemistry 11, McGraw-Hill Text, 2001
5. www.otfchemistry.webs.com