Unit: Chemistry Lesson 2: Describing Chemical Reactions Essential Questions: 1.) What information does a chemical equation contain? 2.) How is mass conserved during a chemical reaction? 3.) What are three types of chemical reactions?

Translate the text message using complete words and sentences! R u doin chem hw? IDK the chem symbol for H20. Txt me later. Thx.

Chemical Equation Information A way to show a Chemical equation chemical reaction, using symbols instead of words

A combination of Chemical formula symbols that represent the elements in a compound Chemical Formulas The formula of a compound identifies the elements in the compound and the ratio of their atoms.

Modeling a Chemical Equation Like a skateboard, a chemical equation has a basic structure. How many complete skateboards can be made from the parts pictured?

Structure of an Equation “Reacts to form” Reactant + Reactant → Product + Product Beginning substances Ending Substances

HNO3 + NaHCO3 --> NaNO3 + CO2 + H2O 2 H2 + O2 ---> 2 H2O How many reactants do the equations have? How many products do the equations have?

Mass and Chemical Reactions The total mass of the Law of conservation substances stays the of mass same before and after the reaction

Conservation of Mass In a chemical reaction, matter is not created or destroyed. What is the mass of iron sulfide produced by this reaction?

Matter can enter or Open system escape to the surroundings Matter does not Closed system enter or leave

Balancing Chemical Equations Textbook pages 176-177

Chemical Reactions Two or more elements Synthesis or compounds combine to make a new substance

Compounds break Decomposition down into simpler products

One element replaces Replacement another element or two elements in different compounds trade places

Types of Reactions What is each type of reaction represented?