Describing Chemical Reactions Lesson 9

Chemical Equations Chemical equation is a short easy way to show a chemical reaction using symbols instead of words Use chemical formulas and symbols to summarize a reaction Formulas H2O CO2 C12H22O11

Fill in the blank Chemical equations use ________________ and ______________ to summarize a reaction Examples of a ______________________ is CO2 and __________ Chemical formulas, symbols, chemical formula, h2o

Structure of an Equation All chemical equation have a common structure Starting substances  reactants New substances  products Reactant + Reactant  Product + Product CaCO3  CaO + CO2

Fill in the blank The substance you start with in a chemical reaction is called the ________________ When the reaction was complete, you have a new substance called the _________________ Reactants, products

Conservation of Mass States that during a chemical reaction, matter is not created or destroyed All atoms present at he star of the reaction are present at the end States that in a chemical reaction, the total mass of the reactants must equal the total mass of the products https://www.youtube.com/watch?v=KKNStFnQGAI

Fill in the Blank The _____________________ states that matter is not created or destroyed the total mass of the ____________ must equal the total mass of the ______________ Conservation of mass, reactants, products

Opened and Closed Systems Open system: matter can enter from or escape to the surroundings Ex. Burning wood in a fire place Products of the wood fire have escape up the chimney and into the room Closed System: matter is not allowed to enter or leave Ex. Apple decaying under a glass dome Products from decay are contained by the glass dome

Fill in the blank In an _______________ matter can enter or escape into is surroundings In a __________________ matter can’t escape Open system, closed system

Open or closed system Water boiling on the stove in a pot Water boiling on the stove in a pot with a lid