Chemical Changes in Matter

Chemical Changes

Chemical Change – a change in matter that makes a NEW substance Examples: Burning, Rusting, & Reacting

You might have a chemical change if you see: Color Change Gas Formation Temperature Change Precipitate Formation

Color Change Iron turns from a shiny silver color to a reddish- brown when it rusts EException! Adding food coloring to water is a physical change because it is a mixture!

Gas Formation Combining vinegar and baking soda makes bubbles Burning paper makes smoke EException! Boiling water makes bubbles, but is a physical change (state change)

Temperature Change Burning wood gets hot Cold packs get cold EException! State changes get hot and cold, but are physical changes

Precipitate Formation Precipitate – a solid that forms when 2 non-solids react Often, the precipitate makes the liquid look cloudy, and later settles at the bottom Lead Nitrate (a liquid) + Potassium Iodide (a liquid) make lead iodide (a yellow solid) When CO 2 (a gas) is combined with limewater (a liquid), solid chalk is formed.