3. Chapter Menu Chemical Reactions Section 9.1Section 9.1Reactions and Equations Section 9.2Section 9.2 Classifying Chemical Reactions Section 9.3Section 9.3 Reactions in Aqueous Solutions Exit Click a hyperlink or folder tab to view the corresponding slides.

4. Section 9-1 Section 9.1 Reactions and Equations Recognize evidence of chemical change. chemical change: a process involving one or more substances changing into a new substance chemical reaction reactant product chemical equation coefficient Represent chemical reactions with equations. Balance chemical equations. Chemical reactions are represented by balanced chemical equations.

5. Section 9-1 Chemical Reactions The process by which one or more substances are rearranged to form different substances is called a chemical reaction.chemical reaction

6. Section 9-1 Chemical Reactions (cont.) Evidence of a chemical reaction –Change in temperature –Change in color –Odor, gas, or bubbles may form.

7. Section 9-1 Representing Chemical Reactions Chemists use statements called equations to represent chemical reactions. Reactants are the starting substances.Reactants Products are the substances formed in the reaction.Products This table summarizes the symbols used in chemical equations.

8. Section 9-1 Representing Chemical Reactions (cont.) In word equations, aluminum(s) + bromine(l) → aluminum bromide(s) reads as “aluminum and bromine react to produce aluminum bromide”.

9. Section 9-1 Representing Chemical Reactions (cont.) Skeleton equations use symbols and formulas to represent the reactants and products. Al(s) + Br(l) → AlBr 3 (s) Skeleton equations lack information about how many atoms are involved in the reaction.

10. Section 9-1 Representing Chemical Reactions (cont.) A chemical equation is a statement that uses chemical formulas to show the identities and relative amounts of the substances involved in a chemical reaction.chemical equation

11. Section 9-1 Balancing Chemical Equations This figure shows the balanced equation for the reaction between aluminum and bromine.

12. Section 9-1 Balancing Chemical Equations (cont.) A coefficient in a chemical equation is the number written in front of a reactant or product, describing the lowest whole-number ratio of the amounts of all the reactants and products.coefficient

13. Section 9-1 Balancing Chemical Equations (cont.)

14. Section 9-1 Balancing Chemical Equations (cont.)

15. Section 9-1 Balancing Chemical Equations (cont.)

16. Section 9-1 Balancing Chemical Equations (cont.) The most fundamental law in chemistry is the law of conservation of mass. Balanced equations show this law.

17. Section 9-1 Balancing Chemical Equations (cont.)

18. A.A B.B C.C D.D Section 9-1 Section 9.1 Assessment Which of the following is NOT a chemical reaction? A.a piece of wood burning B.a car rusting C.an ice cube melting into water D.red litmus paper turning blue

19. A.A B.B C.C D.D Section 9-1 Section 9.1 Assessment What is the coefficient of bromine in the equation 2Al(s) + 3Br 2 (l) → 2AlBr 3 (s)? A.1 B.2 C.3 D.6