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Classifying Chemical Reactions Is useful in predicting products. FIVE BASIC WAYS TO CLASSIFY CHEMICAL REACTIONS:. Synthesis Decomposition Single-Replacement Double-Replacement Combustion. Synthesis Reactions:. Generic Reaction X + Y-->XY
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Classifying Chemical Reactions Is useful in predicting products
FIVE BASIC WAYS TO CLASSIFY CHEMICAL REACTIONS: Synthesis Decomposition Single-Replacement Double-Replacement Combustion
Synthesis Reactions: Generic Reaction X + Y-->XY Definition-Two reactants combine to make one compound. Note: X and Y can be compounds or elements. Analogy- Like a marriage 2 Reactants and 1 Product
Predicting products using synthesis reactions • 1. Li + S→ • 2. Na + Cl₂→ • 3. Br₂ + K →
Decomposition Reactions: The generic formula of a decomposition reaction is: XY --> X + Y In a decomposition reaction, a compound is broken down into two (or more) simpler substances. Analogy-Like divorce 1 Reactant and 2+ Products
Predicting products using Decomposition Reactions • Use of Reference Tables (don’t guess) • ZnS • CaCO₃ • Mg(OH)₂ • H₂SO₄
Single Replacement Reactions • Discovery Education Video
Single Replacement Reactions: A + XY --> AY + X In this type of reaction, one (more active) element replaces a similar element in a compound. Metal replaces metal Non-metal replaces non-metal Aggressive metal wins 1 free element + compound compound + 1 free element Like finding a new girl or boy friend
Li Rb K Ca Na Mg Al Mn Zn Fe Ni SnPb Cu Ag Pt Au Activity Series of Metals Most active metal wins out Activity Series of Halogens F₂ Most active halogen wins Cl₂ Br₂ I₂
Examples of Single Replacement Reactions: 2Al + 3Fe(NO3)2 3Fe + 2Al(NO3)3 Zn + CuCl2 Mg + Pb(NO3)2 Fe + Na3PO4 K + ZnCl2
Double-Replacement Reactions: AB + XY --> AY + XB In a double-replacement reaction, the two compounds exchange places in a solution to form two new compounds. Note: Always ionic compounds or acids as the reactants Like switching partners in square dancing 2 compounds 2 compounds
Predicting products based onDouble Replacement Reactions • Na₂(CO₃)+ CuCl₂→ • BaCl₂+ Na₂SO₄→ • (NH₄)₂S+ Zn(C₂H₃O₂)₂→ • Ca(OH)₂+ HCl→
Combustion reaction Fuel reacts with oxygen to produce heat + carbon dioxide and water. CH₄ + O₂(g) → CO₂ (g) + H₂O(g) + heat Exothermic reaction
Combustion Reactions: When a substance combines with oxygen releasing a large amount of energy in the form of light and heat, it is a combustion reaction. Note: Hydrocarbon fuel is composed of C, H & sometimes O Fuel* + oxygen → carbon dioxide + water Oxygen is needed to Burn things.
Predicting products based on Combustion Reactions • Hexane C₆H₁₄ • Methanol CH₃OH • Glycerol C₃H₈O₃
FIVE BASIC WAYS TO CLASSIFY CHEMICAL REACTIONS: Synthesis 2 reactants1 product (like marriage) Decomposition 1 reactant 2 products (like divorce) Single-Replacement (most aggressive element wins) Double-Replacement (switch partners) Combustion=Burning (need oxygen to burn things)
Practice Reactions • Use the Chemistry Reference Tables