Chemical Chemical ReactionsReactions

88thth 5.1 Chemical Reactions 5.1 Chemical Reactions

Chemical ReactionsChemical Reactions

Physical changes- same substance Physical changes- same substance changing form (solid, liquid, gas)changing form (solid, liquid, gas)

Chemical changes-formation of a Chemical changes-formation of a new substancenew substance

Chemical reaction-a process Chemical reaction-a process where chemical changes occurwhere chemical changes occur

Chemical equations-symbols used Chemical equations-symbols used to describe a reactionto describe a reaction

1. Color change1. Color change 2. Bubbles form2. Bubbles form 3. Light is emitted3. Light is emitted 4. Temperature change4. Temperature change 5. Precipitate forms5. Precipitate forms

Chemical ReactionsChemical Reactions

Reactants-substances that Reactants-substances that reactreact..

Product-new substances created.Product-new substances created. Chemical formulaChemical formula HH22 + O + O2 2 H H22O + OO + O CC22HH44OO22+NaHCO+NaHCO33 (Reactants) (Reactants) NaCNaC22HH33OO22+H+H22O+COO+CO22 (Product) (Product) 6 CO6 CO22 + 6 H + 6 H22O O C C66HH1212OO66 + 6 O + 6 O22

Chemical ReactionsChemical Reactions

Conservation of Mass-the mass Conservation of Mass-the mass of the reactants always equals of the reactants always equals the mass of the productsthe mass of the products

Endothermic reaction-energy Endothermic reaction-energy is absorbed (cold)is absorbed (cold)

Exothermic reaction-energy is Exothermic reaction-energy is released (warm)released (warm)

Physical or Chemical Physical or Chemical ChangeChange

1. Making a cake1. Making a cake 2. Rotting fruit2. Rotting fruit 3. Water 3. Water

evaporatingevaporating 4. Soil erosion4. Soil erosion 5. Boiling an egg5. Boiling an egg 6. Butter melting6. Butter melting 7. Soda freezing7. Soda freezing

8. Making bread8. Making bread 9. Chopping wood9. Chopping wood 10. Burning wood10. Burning wood 11. Chewing food11. Chewing food 12. Silver 12. Silver

tarnishingtarnishing 13. Metal rusting13. Metal rusting 14. Popcorn 14. Popcorn

poppingpopping