SAAT Chemistry

• Chemistry


  Is the study of matter and its changes.
• Analytical Chemistry


  Study of the types and structure of matter.

  Example: food and product quality control.
• Atomic Chemistry


  Study of theories of structure and matter.

  Example: atomic bonds, shapes of orbitals and electronic configuration
• Biochemistry


  Study of matter and processes in living organisms.
• Ozone layer 


  absorbs most of the harmful UV radiation before arriving on Earth
• Ozone gas


  Forms in Stratosphere layer. It's molecule is compose of 3 oxygen atoms (O3).
• Ozone hole


  Is the depletion of the ozone layer over the Antarctic (South Pole) caused by chlorofluorocarbons (CFCs) compounds.
• Chlorofluorocarbons


  Are believed to be harmful to the atmosphere and responsible for climate change.
• Types of Scientific Research

  Theoretical and Applied
• Theoretical Research


  The purpose of theoretical research is to increase our knowledge about things.
• Applied Research


  The purpose of applied research is to solve a real world problem.
• Matter


  Is anything that has mass and occupies space.
• Mass


  Is a measure of the amount of matter in an object (Kg is the unit).
• States of Matter


  Solid

  Liquid

  Gas

  Plasma
• Solid


  Fixed shape and volume, strong forces between particles.
• Liquid


  Can flow, has a fixed volume but takes the shape of its container.
• Gas


  Takes the shape and volume of its container, compressible.
• New State


  Scientists discovered a new state called PLASMA which exists only at extremely high temperatures.
• Physical Properties


  Can be measured without changing the sample composition

  Intensive (qualitative): does not depend on the amount of matter

  Examples: color, taste, density, melting and boiling points

  Extensive (quantitative): depends on the amount of matter

  Examples: length, volume, mass
• Chemical Properties


  The ability of a substance to react with other substances.

  Examples: rusting, burning of wood or tarnishing of silver

  -The inability of matter to react or change is considered a chemical property.

  Example: salt doesn't react with water
• Physical Changes


  Are changes in matter without changing its identity (chemical composition).

  Examples: Breaking glass, Cutting of paper, Diamond polishing and Changing in State
• Physical changes can take two forms

  1. Endothermic: absorb energy (take energy in) melting, evaporation and sublimation.
  2. Exothermic: release enegy energy (give out energy) freezing, condensation and deposition
• What does change of state depend on?

  State of matter depends on surrounding temperature and pressure.
• Melting


  Changing from solid to liquid
• Evaporation


  Change from liquid to gas
• Freezing


  Change from liquid to solid
• Condensation


  Change from gas to liquid
• Sublimation


  Change from solid to gas
• Deposition

  Change from gas to solid
• Density


  M/V

  relationship between mass and volume
• Boiling Point


  Is the temperature at which vapor pressure equals the atmospheric pressure.
• Chemical Changes


  Changes in the structure and properties of substances (identity). New substances form.

  Examples: Burning, Bread mold and decomposition
• Element


  A pure substance that can't be divided into simpler substances by physical or chemical means.

  Examples: Sodium Na, Calcium Ca, Chromium Cr

  -Some gaseous elements are found as diatomic molecules.

  Examples: Hydrogen H2, Nitrogen N2, Oxygen O2
• Compound


  A pure substance that can be decomposed into simpler substances by chemical means.

  Examples: table salt NaCl or water H2O

  -Compound properties are completely different from the properties of its elements.
• Three Fundamental Laws in Chemistry

  Law of conservation of mass, Law of constant proportions, Law of multiple proportions
• Law of conservation of mass


  Mass is neither created nor destroyed in a chemical reaction.
• Law of constant proportions

  Every compound is always made of its elements in a same mass ratio.
• Law of multiple proportions


  When elements combine to form different compounds, then the ratio of masses of one element to a fixed mass of another element is a simple whole number ratio.
• Chemical Reaction


  Rearrangement of atoms to produce new substances.
• Types of Chemical Reactions

  Synthesis, Combustion, Decomposition, Simple displacement, and double displacement