Chemical Reactions (MS-PS1-2) Analyze and interpret data on properties of a substance before and after an interaction to determine if a chemical reaction has occurred.
Chemistry Defined Chemistry is the study of the composition/properties of matter the changes that matter undergoes
Matter Defined Anything that has mass and takes up space (has volume) Made of atoms
Chemistry Defined Chemistry is the study of the composition/properties of matter the changes that matter undergoes
Properties of Matter REMINDER: All matter has 2 types of properties 1.) Physical Properties 2.) Chemical Properties
Examples of Physical Properties Mass Volume Density Color Size Melting and Boiling Point Hardness Odor Taste State of matter Texture Luster (shine) Flexibility Heat (thermal) conductivity Electrical conductivity Solubility Shape Viscosity Ductility Malleability
Examples of Chemical Properties Reactivity Flammability Corrosiveness ability of the substance to combine chemically with other substances ability of the substance to burn Instability Tarnishing Rusting ability of a substance to destroy and damage other substances upon contact the ability of a substance to easily change even under normal environmental conditions the loss of luster due to exposure to air and/or moisture ability to oxidize with water
Chemistry Defined Chemistry is the study of the composition/properties of matter the changes that matter undergoes
Changes in Matter There are two basic ways matter can change: 1.) Physically 2.) Chemically
Quiz time! What type of change is most likely occurring here? How do you know? Think F.A.R.T.S. and Fireworks!
Quiz time! What type of change is most likely occurring here? How do you know?
Quiz time! What type of change is most likely occurring here? How do you know?
In order for matter to chemically change......a CHEMICAL REACTION MUST TAKE PLACE.
Chemical Reactions are Everywhere Cooking Baking
Chemical Reactions are Everywhere Hair Dye Auto Fuel
Chemical Reaction Defined Process in which matter chemically changes because two or more substances react to form new substances
How do you know when a chemical reaction takes place? Color Change Precipitate (Solid) Formation
How do you know when a chemical reaction takes place? Gas Formation Odor
How do you know when a chemical reaction takes place? Temperature Change Change in Acidity
Evidence that Matter is Chemically Changing Due to a Chemical Reaction
F.A.R.T.S.?!?!?!? Reactants Summarized Bread Cheese Toppings of Choice Tomato Sauce When You Eat a Slice of Pizza Products Summarized 59% Nitrogen 21% Hydrogen 9% Carbon dioxide 7% Methane 4% Oxygen 1% Hydrogen sulfide gas
Evidence that Matter is Chemically Changing Due to a Chemical Reaction Fizzing/Bubbles Formation of gas Aroma Replacement Temperature new Substance(s) Formation of a solid Sound Light Color Change Fireworks!
New Substance(s) Form During a Chemical Reaction What evidence proves that new substances formed during our demonstration? New substances will have completely different properties than the orignial substances + +
New substances will have completely different properties than the orignial substances What if you are unable to observe the properties of the new substances? Or, what if the properties look like the reactants? Liquid Colorless Odorless Liquid Colorless Odorless Solid Yellow Denser than liquid
Modeling Chemical Reactions Chemical Equations: used to show chemical reactions, and to prove that new substances form during a reaction Reactants: substance(s) at the beginning of the reaction; left side of arrow Products: substance(s) at the end of the reaction; right side of arrow Exploding Pumpkin Reactants Products CaC 2 (s) + 2H 2 O(l) Ca(OH) 2 (s) + C 2 H 2 (g)
Exploding Pumpkin Exploding Pumpkin CaC 2 (s) + 2H 2 O(l) Ca(OH) 2 (s) + C 2 H 2 (g) Reactants Products Name Calcium Carbide Water Calcium Hydroxide + + Acetylene Gas Properties Powder Solid Gray Highly Reactive Colorless Odorless Liquid Powdered Solid White Flammable Gas Colorless Odorless + +
Symbols Used in Chemical Equations CaC 2 (s) + 2H 2 O(l) Ca(OH) 2 (s) + C 2 H 2 (g) Symbol 2H 2 O Purpose Example of a chemical formula; identifies substances in the reaction and the amount needed for reaction to occur + Separates more than one reactant or product; say plus (s) Separates reactants from products; indicates direction of reaction; say yields (makes) Identifies a solid state (aq) (l) (g) Identifies a substance that is dissolved in water; aqueous solution Identifies liquid state Identifies gas state