Types of Reaction and Predicting Reactions

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Types of Reaction and Predicting Reactions

• Concept Presentation
• Winnie Ho
• HS Science
• Instructors Janine Extavour Marty Zatzman

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Goal of this presentation

• Grade 10 teachers
• - Differences between Gr 10 and 11 and how to
  prepare our students
• Grade 11 teachers
• What Gr 10 students know and common roadblocks in
  this topic

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Teaching sequence in 11U

• Unit 1- Matter, Chemical trends, and Chemical
  Bonding
• Unit 2 - Chemical reaction
• Prior knowledge
• - Ionic compounds and covalent molecules
• - Nomenclature
• - Balancing equation
• - Classifying reactions

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Curriculum expectation
Grade 10 Chemistry expectations on types of
reaction
C2.3 investigate simple chemical reactions, including synthesis, decomposition, and displacement reactions, and represent them using a variety of formats (e.g., molecular models, word equations, balanced chemical equations)
C3.5 describe, on the basis of observation, the reactants in and products of a variety of chemical reactions, including synthesis, decomposition, and displacement reactions (e.g., reactions occurring when magnesium burns or in the production of oxygen from hydrogen peroxide the reaction of iron and copper sulphate reactions occurring when fossil fuels burn)
Grade 11 Chemical reaction (selected
expectations on types of reaction)
C2.4 predict the products of different types of synthesis and decomposition reactions (e.g., synthesis reactions in which simple compounds are formed synthesis reactions of metallic or non-metallic oxides with water decomposition reactions, in which a chemical compound is separated into several compounds)
C2.5 predict the products of simple displacement reactions, using the metal activity series and the halogen series.
C2.6 predict the products of double displacement reactions (e.g. formation of precipitates or gases neutralization)
C2.7 design an inquiry to demonstrate the difference between a complete and an incomplete combustion reaction
C2. 10 plan and conduct an inquiry to demonstrate a simple displacement reaction, using elements from the metal activity series
C3.1 identify various types of chemical reactions, including synthesis, decomposition, single displacement, double displacement, and combustion
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Comparison

• Grade 10
• - Classifying all four reaction types
• Neutralization

• Grade 11
• All four reaction types
• Activity series
• Solubility rules
• Neutralization
• Combustion
• Nuclear reactions
• Focus on lab inquiry
• Prediction of products

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Diagnostic assessment

• nitric acid potassium hydroxide ? ____________
  water Type ___________
• zinc ___________ ? zinc nitrate solution
  copper Type ___________
• __________ acid zinc carbonate ? zinc sulfate
  water carbon dioxide Type ___________
• calcium chlorine ? _____________________
  Type ___________
• magnesium hydrochloric acid ? __________
  hydrogen Type ___________
• propane oxygen ? _____________________
  water Type ___________

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Reaction Type General Chemical Equation
Synthesis A B ? AB
Decomposition AB ? A B
Single Displacement M BC ? MC B N BC ? BN C
Double Displacement AB CD ? AD CB
Combustion CxHy _O2 ?_ CO2 _ H2O
Sodium and Chlorine reacts to form Sodium chloride
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Roadblock 1

• Failure to connect symbols to the actual elements
• A B ? AB
• A can represent an element, a diatomic molecule,
  or a compound.
• The ordering of the symbols is important.

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Can you find the mistakes?
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Macroscopic
Microscopic
Symbolic
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Roadblock 2

• Predicting synthesis vs. combustion rxn

Grade 10 synthesis reaction

• Grade 11 combustion reaction
• Reaction of a substance with oxygen, producing
  oxides and energy (Nelson text)
• Combustion of magnesium as an example of a
  synthesis reaction
• Exothermic reaction

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Synthesis Reaction!
Brad Angelina ? Brangelina
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Tom Katie ? TomKat
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Roadblock 3

• Predicting single displacement reactions

Zn(s) CuSO4(aq)--gt
ZnSO4(aq) Cu(s)
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Video
Safety concerns Demo Li, Na, K with
water ?Goggles, small quantity
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Alternatives
M BC ? MC B M metal
element N BC ? BN C N
non-metal element
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Roadblock 4

• Predicting double displacement reactions

If a reaction does not produce a precipitate, a
gas, or water, then it is not a DD reaction.
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Solubility table
KOH(aq) NH4Cl (aq)--gt
No Reaction
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KOH(aq) NH4Cl (aq)--gt no reaction
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Use of states symbols are important

• More consistent usage of state symbols in grade
  10 when writing out chemical equations.
• e.g., NaOH(aq) HCl(aq) ? H2O (l) NaCl (aq)

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Societal implications
Synthesis reaction Rusting, Galvanization, Alloy
Decomposition reaction Production of sodium using electrolysis of molten sodium chloride
Single displacement reaction Extracting metals, smelting process, Bromine compound as fire retardant
Double displacement reaction Geochemistry (solubility rules allows students to understand why some elements exist as compounds in nature), corrosion of statues
Combustion Greenhouse effect
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Computer resources

• Gizmos
• Metals in aqueous solutions simulation

Differentiated instruction

• Computer simulation (modified versions of
  activities)
• Video
• Group work on making connections issues

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Thank you.