types of reaction and predicting reactions concept presentation winnie ho hs science instructors...
TRANSCRIPT
Types of Reaction and Predicting Reactions
Concept PresentationWinnie Ho HS Science
Instructors Janine Extavour & Marty Zatzman
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
Teaching sequence in 11U
•Unit 1- Matter, Chemical trends, and Chemical Bonding
•Unit 2 - Chemical reactionPrior knowledge: - Ionic compounds and covalent
molecules - Nomenclature - Balancing equation - Classifying reactions
Curriculum expectationGrade 10 – Chemistry expectations on types of reaction
C2.3investigate 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)
C2.4predict 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
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
Diagnostic assessment1. nitric acid + potassium hydroxide ____________+
water Type: ___________2. zinc + ___________ zinc nitrate solution + copper
Type: ___________3. __________ acid + zinc carbonate zinc sulfate +
water + carbon dioxide Type: ___________4. calcium + chlorine _____________________
Type: ___________5. magnesium + hydrochloric acid __________ +
hydrogen Type: ___________6. propane + oxygen _____________________ + water
Type: ___________
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
Roadblock #1Failure 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.
Roadblock #2Predicting 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
Video
Safety concerns:
Demo: Li, Na, K with water
Goggles, small quantity
Roadblock #4Predicting double displacement reactions
If a reaction does not produce a precipitate, a gas, or water, then it is not a DD reaction.
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)
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
Computer resources• Gizmos
• Metals in aqueous solutions simulation
Differentiated instruction• Computer simulation (modified
versions of activities)• Video• Group work on making connections
issues