Introduction%20to%20Chemistry

1
Introduction to Chemistry

• SNC2DI

2
Organization of Matter
3
Physical Properties

• A physical property describes the substance
• E.g.
• State
• Hardness
• Melting point
• Boiling point
• Odour
• Solubility
• Colour
• Malleability
• Ductility
• Etc.

4
Chemical Property

• A chemical property is a description of how the
  substance reacts to form a new substance.
• E.g.
• How it reacts with acid
• How it reacts with water
• How it reacts with oxygen
• Etc.

5
Physical Change

• A physical change is when the original substance
  does not turn into a new substance but does
  change form.
• E.g.
• Ripping a piece of paper
• Dissolving a salt
• Melting ice

6
Chemical Change

• When a substance changes from one substance into
  another, it is a chemical change.
• E.g.
• Baking soda in acid
• Iron exposed to oxygen
• Combustion

7
How to Recognize a Chemical Change

• Clues that a chemical change has occurred.
• A new colour appears
• Heat or light is given off
• Bubbles of gas are formed
• A precipitate (solid) forms in a liquid
• The change is difficult to reverse
• E.g. 2H2(g) O2(g) ? 2H2O(l)

8
Chemical Tests

• You can use chemical change to perform a chemical
  test to determine if a substance is present.
• Glowing splint used to indicate if oxygen is
  present
• A burning splint is used to indicate if hydrogen
  is present
• Limewater can be used to indicate if carbon
  dioxide is present
• Cobalt chloride paper can be used to indicate if
  water is present
• A flame test can tell which type of metal is
  present

Flame test for Li
9
Homework

• Read section 5.1
• Answer questions 2-8 on page 178

10
Credits

• http//commons.wikimedia.org/wiki/FileSnow_crysta
  ls_2b.jpg
• http//commons.wikimedia.org/wiki/FileMagnesium_S
  parks.jpg
• http//commons.wikimedia.org/wiki/FileMelting_ice
  cubes.gif
• http//commons.wikimedia.org/wiki/FileLighting-ma
  tch.gif
• http//commons.wikimedia.org/wiki/FileFlammenfärb
  ungLi.png