Classifying Chemical Reactions Is useful in predicting products

FIVE BASIC WAYS TO CLASSIFY CHEMICAL REACTIONS: 1. Synthesis 2. Decomposition 3. Single-Replacement 4. Double-Replacement 5. 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. 2 Reactants and 1 Product Analogy- Like a marriage

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. 1 Reactant and 2+ Products Analogy-Like divorce

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 1 free element + compound  compound + 1 free element Aggressive metal wins Like finding a new girl or boy friend

Li Rb K Ca Na Mg Al Mn Zn Fe Ni Sn Pb Cu Ag Pt Au Activity Series of Metals Most active metal wins out Activity Series of Halogens F ₂Most active halogen wins Cl₂ Br₂ I₂

Examples of Single Replacement Reactions: 2Al + 3Fe(NO 3 ) 2  3Fe + 2Al(NO 3 ) 3 Zn + CuCl 2  Mg + Pb(NO 3 ) 2  Fe + Na 3 PO 4  K + ZnCl 2 

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 2 compounds  2 compounds Like switching partners in square dancing

Predicting products based on Double 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 Oxygen is needed to Burn things. Fuel* + oxygen → carbon dioxide + water

Predicting products based on Combustion Reactions Hexane C ₆H₁₄ Methanol CH₃OH Glycerol C₃H₈O₃

FIVE BASIC WAYS TO CLASSIFY CHEMICAL REACTIONS: 1. Synthesis 2 reactants  1 product (like marriage) 2. Decomposition 1 reactant  2 products (like divorce) 3. Single-Replacement ( most aggressive element wins) 4. Double-Replacement (switch partners) 5. Combustion =Burning (need oxygen to burn things)

Practice Reactions Use the Chemistry Reference Tables