Transcript Misconceptions in General Chemistry Broader Study Skills

Misconceptions in General Chemistry
Broader Study Skills / Behavioural
• instructor misconceptions of students’ knowledge from
high school
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Math 30 / Chem 30 are often taken in grade 11
80 min/day for 12 weeks
RDC study found Math 30 to be the most important factor
administering Chemistry Concept Inventory to instructors
(all levels) to assess their misconceptions
• comprehension (text book and questions)
– teaching students how to read science
• integrating graphs & equations into reading the text
• stopping & thinking about processes/equations
• understanding information in graphs
– students don’t know where to look for information in a graph
• using the index
Broader Study Skills / Behavioural
• misconception about student motivation
– most of them are not like us! chemistry is not a priority in
first year non-majors!
• student misconception about required work
– passed high school with rote memorization (e.g., studying
for the 5 (or 7) question types used by AB Education in
provincial test)
– not used to scheduling self-study time
– think they know it all (repetition from high school)
– challenging to get them to comprehension, application
• misconception about student learning: “Students will
learn what we teach”
– no..mostly will only learn what we test
– “assessment is the tail that wags the dog”
Broader Study Skills / Behavioural
• student misconception of “easy problems only” in
lecture
– watching the expert make no mistakes
– they can follow (but maybe not lead so well)
• student misconception: don’t need to know
vocabulary/jargon
• student misconception of separation of disciplines
– “why is general chemistry more like physics?”
– “chemistry is a math course”
– instructor misconception of how general chemistry should
be taught (content phys chem heavy)?
General Misconceptions
• misconception of size/scale
– chemistry is unfathomable in magnitude
• getting across just HOW small an atom is
– Powers of 10 video/interactive website
– Stacey’s comparison of 1 mol paperclips vs. money vs. water
• misconception that chemistry is bad
– inform about quantity (toxicity is in the dose)
– clearing up misconceptions: use break time or 5 min at
beginning of last lecture every week
• chemistry in the news
• topic of interest related or unrelated to current lecture
• resources such as Joe Schwarcz’ books
• misconception that a proton exists as H+ or H3O+
Misconceptions about Scientific Method
• we don’t communicate that we are teaching models,
don’t communicate scientific method
• “science as the fountain of knowledge”,
misconception that science is about facts, wrong &
right answers
– science is ongoing! it’s happening right now!
– confused that something called a “law” can fail
Heat, Energy, Temperature Misconceptions
• breaking bonds produces energy
– biology: ATP -> ADP + energy
• heat, energy, temperature
– terms of general use, students have preconceptions
• hard to redefine precisely, in contrast to new terms
• compare: strong vs. concentrated (e.g., coffee)
– heat is misconceived as a noun by both
• Teaching aid: Youtube Eureka #21 Heat vs. T
Physical Transitions Misconceptions
• misconceptions/concepts start early
– AB 5th grade is about half of first year without math
• difference between melting and dissolution, liquid and
aqueous
• instructor misconception: students have particle view of
matter
– matter is bulk to students
• visualization: initiative at King’s – see kcvs.ca for examples
• Odyssey (~$75) visualization software
– e.g. linear vs. bent H2O - properties come from structure
• using visualizations: test what you teach!
– suggestion: project coloured images on screen during exam
Teaching Aids: Children’s Ideas and the Learning of Science by Rosalind Driver et al.
Talanquer, V. et al. “A2: Element or Compound” J. Chem. Ed. 2007, 84, 880.
Stoichiometry and limiting reagents
• how to teach this best?
– sandwich example (bread, cheese, meat)
– macaroni/choc chip cookie example (how much of each
ingredient)
– misconception: students transfer the process
(compartmentalization issue, as in K and other areas)
• again, need to get to particle view of matter
– students don’t make connections between letters/symbols
and particles (maybe we don’t either until we teach)
• Teaching Aids:
– See publications by Miles Pickering and Mary Nockley(?)
– George M. Bodner, “I have found you an argument: The
conceptual knowledge of beginning chemistry graduate
students” J. Chem. Ed. 1991, 68, 385.
Equilibrium Misconceptions
• like heat/T, there is a meaning attached already
– misconception: equilibrium means equal mass (not rate)
– Stacey’s demo: 2 fish tanks (one empty, one full)
2 beakers scooping water from either side to the other
ask students to predict, when equilibrium is reached
• equilibrium problems ALL look different to some
students
Electrochemistry Misconceptions
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where do electrons come from? (electron transfer)
concept of potential
necessity in 1st year?
helpful doodles to show electrons transferring in or
out of electrodes, corrosion and plating at electrodes
etc.
• Literature tip: T. J. Greenbowe & M. J. Sanger
Significant Figures
• misconception/disagreement regarding
importance
– order of magnitude vs. actual sig. figs.
• includes ability to evaluate an answer for validity
– our obligation goes beyond just teaching chemistry
(but how far?)
– introduce concept in context in labs (+ use in lecture)
• student misconception of meaning/origin
– math rules come from physical reality of
measurement
– introduced too early in text book, needs more context
(lab)
Lab – Lecture Connectivity
• students expect a link – whose misconception?
– issue of integrating early lectures with lab
– effort on side of lecturer
• labs as concept reinforcement – misconception
about how we learn?
– learning by doing: discovery labs
• closer to scientific method / development of models
• possible to pick up student data in lecture (.:relevance)