Today’s Objective: The student will be able to identify the 4 types of equations in a written assignment.

Reactions Changes in matter are described by: Physical changes Chemical Changes

Changes in Matter Physical changes Does not become new substance Can be change in shape, size, or texture Can also be changes in state i.e. melting

Changes in Matter Chemical Changes Changes create something new Produces new product such as gas Also called chemical reactions

Chemical Reactions Chemical Reaction requires: Bonds to break Atoms will rearrange New bonds form New products are made

Clues to a Chemical Reaction 1. Gas Formation – bubbling or fizzing 2. A new solid forms called a precipitate 3. Color change 4. Energy change – gets hotter or colder

Changes in Energy Either absorbs or releases energy Endothermic – energy is absorbed, product becomes hotter Exothermic – energy is released, product becomes colder

Types of Reactions Combustion Synthesis Decomposition Single Replacement Double Replacement

Combustion One of its reactants is Oxygen. Its products include H2O + CO2

Synthesis Reactions 2 or more chemicals combine to form a single compound Na + Cl => NaCl

Decomposition Reaction A single compound breaks apart to 2 or more smaller parts. NaCL => Na + Cl

Single Replacement Reaction A single element is combined with a compound. After reaction, a new element is single and you have a new compound NH3 + I2 => N2I6 + H2

Double-replacement reaction Begin with two compounds. After reaction, you have 2 new compounds. NaOH + KNO3 => NaNO3 + KOH

Example of Double-Replacement Reaction Example: Sodium chloride (salt) reacts with Silver Nitrate and splits up to make Sodium Nitrate and Silver Chloride.