1 of 15

Slide Notes

DownloadGo Live

Chemical Reactions #4

Published on Jan 21, 2016

No Description

PRESENTATION OUTLINE

Law of conservation of matter
Matter is neither created nor destroyed, it can only be changed.

2 main types of observable evidence of chemical reactions:
Formation of new substance and change in energy.

Photo by katerha

Formation of new substance

  • Color change
  • Bubbles
  • Mold
  • Precipitate:solid that forms from 2 liquids
Photo by CIMMYT

Change in energy

  • During chemical reactions energy is either released or absorbed
  • Endothermic: energy absorbed (heat is added)
  • Exothermic: energy released (heat given off)
Photo by Chuckumentary

All chemical reactions require a minimum amount of energy to start....activation energy!
Typically exothermic reactions require less energy = more likely to occur.

Reactions can be controlled

  • Surface area
  • Temperature
  • Concentration amount / volume
  • Catalysts substance that lowers activation energy (enzymes) speeds up reaction
  • Inhibitors: slows down reaction. Prevents reactants from coming together (preservatives)

EQUATION STRUCTURE

REACTANT+REACTANT ➡️ PRODUCT+PRODUCT

Because of the Law of Conservation of Mass, all chemical equations must be balanced, must show the same number of each type of atom on both sides of the equation.

Photo by mrlanham

TYPES OF CHEMICAL REACTIONS

  • Synthesis
  • Decomposition
  • Single Replacement
  • Double Replacement
  • Combustion
  • Acid/Base (neutralization)
Photo by Iain George

SYNTHESIS

2 OR MORE ELEMENTS/COMPOUNDS COMBINE TO CREATE MORE COMPLEX SUBSTANCE
Photo by EMSL

DECOMPOSITION REACTION

COMPOUND IS BROKEN DOWN TO SIMPLER PRODUCT
Photo by skycaptaintwo

SINGLE REPLACEMENT

ONE ELEMENT REPLACES ANOTHER ELEMENT IN A COMPOUND
Photo by pianetatschai

DOUBLE REPLACEMENT

2 ELEMENTS REPLACE EACH OTHER IN DIFFERENT COMPOUNDS
Photo by skycaptaintwo

Combustion

FUEL PLUS OXYGEN PRODUCES HEAT/LIGHT AND WATER AND CO2

Acid/Base

ACID PLUS A BASE NEUTRALIZE TO PRODUCE WATER AND SALT
Photo by agroffman