1. Chemical Reactions and Balancing Chemical Equations

2. Opening Activity Pre-assessment: Write out and balance the following chemical reaction: ___C 3 H 8 + ___O 2  ___CO 2 + ___H 2 O 4/28

3. Chemical Reactions chemical reaction A chemical reaction is process where starting substances are transformed to a different substance. Law of Conservation of Energy/Matter Law of Conservation of Energy/Matter – matter cannot be created nor destroyed, only changed. Chemical reactions (equations) MUST be balanced (same number of same atoms on both sides). reactants Starting substances are called reactants products Final substances are called products Reactants  Products(  means make, yield, NOT equal to)

4. 5 Basic Chemical Reactions Decomposition Decomposition – 1 compound breaks apart AB  A + B Synthesis Synthesis – 2 smaller ions make 1 larger compound C + D  CD Combustion Combustion – reacts with oxygen gas to release heat energy X + O 2  XO + heat energy Single Replacement Single Replacement – 1 set of ions switch places EF + G  EG + F (G and F switched places) Double Replacement Double Replacement – 2 sets of ions switch places HK + JL  HL + JK (H and K switch with J and L)

5. Let’s complete the video worksheet together as a class. https://www.youtube.com/watch?v=nsEkKIiOz7Q Tricky chemical names (you’ll learn these in high school): Potassium Chromate = K 2 CrO 4 Silver Nitrate = AgNO 3 Ethanol = C 2 H 6 O