1. Indications of a Chemical Reaction

2. What do we look for to determine if a chemical reaction is occurring?

3. Evolution of heat and light

4. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light –The burning of wood or coal

5. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light –The burning of wood or coal –The burning of magnesium

6. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light –The burning of wood or coal –The burning of magnesium –This is not always an indication of a chemical reaction.

7. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light –The burning of wood or coal –The burning of magnesium –This is not always an indication of a chemical reaction. Phosphorescence or fluorescence produce light without a chemical reaction.

8. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light –The burning of wood or coal –The burning of magnesium –This is not always an indication of a chemical reaction. Phosphorescence or fluorescence produce light without a chemical reaction. Compression of gases produce heat without a chemical reaction.

9. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light

10. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas

11. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas –Gas bubbles when two things are mixed

12. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas –Gas bubbles when two things are mixed Zinc and acid

13. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas –Gas bubbles when two things are mixed Zinc and acid Baking soda and vinegar

14. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas

15. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate

16. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate –A solid formed when mixing two things

17. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate –A solid formed when mixing two things Zinc sulfate and barium nitrate

18. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate –A solid formed when mixing two things Zinc sulfate and barium nitrate Potassium iodide and lead nitrate

19. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate

20. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change

21. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change –Rusting causes iron to go from silvery to red

22. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change

23. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change Formation of water

24. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change Formation of water –Burning hydrocarbons produce carbon dioxide and water.

25. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change Formation of water –Burning hydrocarbons produce carbon dioxide and water. –Combining acids and bases form water.

26. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change Formation of water

27. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change Formation of water –The formation of water does not necessarily indicate a chemical reaction.

28. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change Formation of water –The formation of water does not necessarily indicate a chemical reaction. Water condenses on a cold glass.

29. What do we look for to determine if a chemical reaction is occurring? Evolution of heat and light Production of a gas Formation of a precipitate Color change Formation of water