Unit 4: Lesson 3 CLASSIFYING REACTIONS

Synthesis Reaction  Only has one product  Two or more substances coming together and bonding  How would you determine if a reaction is a SYNTHESIS reaction?

Decomposition Reaction  A single compound breaks down into two or more products  Only one REACTANT  Can occur slowly  Can be sped up with a CATALYST  Catalysts do not chemically change their composition  They are not a reactant or product  What clue would you look for determine if a reaction is a DECOMPOSITION reaction?

Single Replacement Reaction  Write the following reaction:  Solid Zinc reacts with Copper (II) Nitrate to form Solid Copper and Zinc Nitrate  Zn (s) + Cu(No 3 ) 2 (aq) → Cu (s) + Zn(No 3 ) 2 (aq)

Single Placement Reaction – cont;  Cu(NO 3 ) 2 dissolves  Separates into Cu 2+ cations (positive ions) and NO 3 - anions (negative ions)  Zn bonds to NO 3 - anions  Forms Zn(No 3 ) 2 as a product  Two Cations ( positive ions) switch places

Single Replacement – General Equation & Questions  What do you look for to pick out a Single Replacement Reaction?  Why is the General Equation NOT:  A + BC → C + AB?  Hint: It has to do with charges  Can “C” be a Single Element?

Double Replacement Reactions  Two compounds react  Form two new compounds  Positive ions ( cations ) switch places  Write the following reaction:  Aqueous Sodium Sulfide and Cadmium Nitrate produce a yellow precipitate of Cadmium Sulfide  Na 2 S (aq) + Cd(NO 3 ) 2 (aq) → CdS (s) + 2NaNO 3 (aq)

YOUR TURN!!  Write the General Equation

Combustion Reaction  Hydrocarbon or carbohydrate react with oxygen gas to produce carbon dioxide and water  Hydrocarbon: compound composed of hydrogen and carbon  Examples:  Methane – CH 4  Propane – C 3 H 8  Butane – C 4 H 10  Carbohydrate : compound composed of carbon, hydrogen and oxygen

Combustion Reaction – General Equations