1. We've already learned how and why elements combine to form different compounds. Now it's time to move on to bigger and better things! Let's learn about how to describe what happens when elements and compounds interact with one another to form new substances. Chemical Reactions and Equations

2. Chemical Reactions Chemical reactions are part of our daily lives. From cooking in the kitchen, to driving a car, these reactions are commonplace. BUT check out these more exotic and amazing reactions!

3. Potassium Chlorate and Gummy Bear https://www.youtube.com/watch?feature=pl ayer_embedded&v=txkRCIPSsjM Potassium Chlorate is often used in fireworks and explosives. When it is heated to melting point, any item added to it will cause a rapid disintegration in the form of an explosion (as we see in the video above).

4. Sodium Acetate Super Saturation https://www.youtube.com/watch?feature=playe r_embedded&v=uy6eKm8IRdI

5. Lesson Objectives: 1.Explain what happens during a chemical reaction 1.Identify the reactants and products in any chemical reaction 1.Use the common symbols (s), (l), (g), (aq), and “  ” appropriately

6. Introduction Chemical reaction: occurs when one or more chemicals react to become different chemicals. Atoms rearrange, bonds are broken, new bonds are formed, and the chemical's identity is actually changed. Reactants: the substances that are present at the beginning of a reaction. Products: the substances that are present at the end of a reaction

7. Chemical Equations The best way to represent what happens during a chemical reaction is by using a chemical equation. We've all seen them, even if it was just in cartoons or reruns of Bill Nye. You know, the good 'ole A + B → C.

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9. 1.Identify the reactants and the products 2.Place the reactants on the left 3.Place the products on the right 4.Place an arrow between them Steps For Writing Chemical Equations

10. Word Equations Chemical names are used to represent the reactants and products in a chemical reaction. Ex. An aqueous solution of calcium nitrate is added to an aqueous solution of sodium hydroxide to produce solid calcium hydroxide and an aqueous solution of sodium nitrate.

11. Skeletal Equations Chemical formulas are used instead of chemical names for reactants and products, and symbols are used to indicate the phase of each substance Ex. Ca(NO3 ) 2 (aq) + 2NaOH(aq) → Ca(OH) 2 (s) + 2NaNO 3 (aq)

12. Skeletal Equations When sulfur dioxide is added to oxygen, sulfur trioxide is produced. In the chemical equation shown below, sulfur dioxide and oxygen (SO 2 and O 2 ) are reactants, and sulfur trioxide (SO 3 ) is the product.

13. Common Symbols in Chemical Reactions

14. Let’s Try it in Reverse! Look at the following reaction in shorthand notation and describe the reaction in words: Cu(s) + AgNO3(aq) → Cu(NO3 )2(aq) + Ag(s)

15. Let’s Try it in Reverse! Look at the following reaction in shorthand notation and describe the reaction in words: Cu(s) + AgNO3(aq) → Cu(NO3 )2(aq) + Ag(s)

16. Let’s Try it in Reverse! Look at the following reaction in shorthand notation and describe the reaction in words: Cu(s) + AgNO3(aq) → Cu(NO3 )2(aq) + Ag(s)

17. Let’s Try it in Reverse! Look at the following reaction in shorthand notation and describe the reaction in words: Cu(s) + AgNO3(aq) → Cu(NO3 )2(aq) + Ag(s) Answer: solid copper reacts with an aqueous solution of silver nitrate to produce a solution of copper(II) nitrate and solid silver

18. Example 1 Write the following skeletal equation as a word equation: HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)

19. Example 1 Write the following skeletal equation as a word equation: HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) An aqueous solution of hydrochloric acid reacts with an aqueous solution of sodium hydroxide to produce an aqueous solution of sodium chloride and liquid water.

20. Example 2 Write the following word equation as a skeletal equation: Gaseous propane, C3H8, burns in oxygen gas to produce gaseous carbon dioxide and liquid water.

21. Example 2 Write the following word equation as a skeletal equation: Gaseous propane, C3H8, burns in oxygen gas to produce gaseous carbon dioxide and liquid water. C 3 H 8 (g) + O 2 (g) → CO 2 (g) + H 2 O(l)

22. Example 3 Write the following word equation as a skeletal equation: Hydrogen fluoride gas reacts with an aqueous solution of potassium carbonate to produce an aqueous solution of potassium fluoride, liquid water, and gaseous carbon dioxide.

23. Example 3 Write the following word equation as a skeletal equation: Hydrogen fluoride gas reacts with an aqueous solution of potassium carbonate to produce an aqueous solution of potassium fluoride, liquid water, and gaseous carbon dioxide.

24. Example 3 Write the following word equation as a skeletal equation: Hydrogen fluoride gas reacts with an aqueous solution of potassium carbonate to produce an aqueous solution of potassium fluoride, liquid water, and gaseous carbon dioxide. HF(g) + K 2 CO 3 (aq) → KF(aq) + H 2 O(l) + CO 2 (g)

25. Summary A chemical reaction is the process in which one or more substances are changed into one or more new substances. Chemical reactions are represented by chemical equations. Chemical equations have reactants on the left, an arrow that symbolizes “produces”, and the products on the right.