Chemical Reactions CHAPTER the BIG idea CHAPTER OUTLINE Chemical reactions form new substances by breaking and making chemical bonds. Chemical reactions alter arrangements of atoms. 9.1 The masses of reactants and products are equal. 9.2 Chemical reactions involve energy changes. 9.3 NEW CHAPTER CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME SECTION OUTLINE SECTION OUTLINE reactant chemical reaction Chemical reactions alter arrangements of atoms. precipitate product catalyst 9.1 CHAPTER RESOURCES CHAPTER RESOURCES CALIFORNIA Content Standards 8.5.a Students know reactant atoms and molecules interact to form products with different chemical properties. 8.5.c Students know chemical reactions usually liberate heat or absorb heat. 8.5.d Students know physical processes include freezing and boiling, in which a material changes form with no chemical reaction.

VOCABULARY KEY CONCEPT CHAPTER HOME SECTION OUTLINE SECTION OUTLINE reactant chemical reaction Chemical reactions alter arrangements of atoms. Chemical changes occur through chemical reactions. precipitate product catalyst 9.1 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME SECTION OUTLINE SECTION OUTLINE reactant chemical reaction Chemical reactions alter arrangements of atoms. Chemical reactions change reactants into products. Chemical changes occur through chemical reactions. Evidence of a chemical reaction includes a color change, the formation of a precipitate, the formation of a gas, and a change in temperature. precipitate product catalyst Reactants–bonds broken oxygen (O 2 ) (CH 4 ) methane + Products–new bonds formed carbon dioxide (CO 2 )(H 2 O) water CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME SECTION OUTLINE SECTION OUTLINE reactant chemical reaction Chemical reactions alter arrangements of atoms. Chemical reactions change reactants into products. Chemical changes occur through chemical reactions. Evidence of a chemical reaction includes a color change, the formation of a precipitate, the formation of a gas, and a change in temperature. precipitate product catalyst 9.1 VISUALIZATION Observe how changing the concentration of a reactant can change the rate of a reaction. CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME Physical/Chemical changes Physical changes may change some of the properties of a substance, but it is still the same substance. Chemical changes make a new substance.

VOCABULARY KEY CONCEPT CHAPTER HOME The process by which chemical changes occur. -atoms are rearranged, and chemical bonds are broken and formed. chemical reaction KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions alter arrangements of atoms. reactant chemical reaction precipitate product catalyst 9.1 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME A substance that is present at the beginning of a chemical reaction and is changed into a new substance. reactant KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions alter arrangements of atoms. reactant chemical reaction precipitate product catalyst 9.1 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME A substance formed by a chemical reaction. A product is made by the rearrangement of atoms and bonds in reactants. product KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions alter arrangements of atoms. reactant chemical reaction product precipitate catalyst 9.1 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME Chemical reactions alter arrangements of atoms. Chemical reactions change reactants into products Reactants–bonds broken oxygen (O 2 ) (CH 4 ) methane + Products–new bonds formed carbon dioxide (CO 2 )(H 2 O) water +

VOCABULARY KEY CONCEPT CHAPTER HOME Types of Chemical Reactions Synthesis reaction-a new product is formed by the combination of simpler reactants. Decomposition reaction, a reactant breaks down into simpler products, which can be elements or compounds.

VOCABULARY KEY CONCEPT CHAPTER HOME Types of Chemical Reactions Combustion reaction, one reactant is always oxygen and involves burning which gives off a lot of energy.

VOCABULARY KEY CONCEPT CHAPTER HOME Evidence of a Chemical Reaction Evidence of a chemical reaction includes: -color change -the formation of a precipitate -the formation of a gas -a change in temperature.

VOCABULARY KEY CONCEPT CHAPTER HOME The rates of chemical reactions can vary. Physical Factors- Increasing concentration, surface area, or temperature of reactants can increase the speed of reaction. Catalyst- A substance that increases the rate of a chemical reaction but is not consumed in the reaction.

VOCABULARY KEY CONCEPT CHAPTER HOME A substance that increases the rate of a chemical reaction but is not consumed in the reaction. catalyst KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions alter arrangements of atoms. reactant chemical reaction precipitate product catalyst 9.1 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME

VOCABULARY KEY CONCEPT CHAPTER HOME n. A solid substance that forms as a result of a reaction between chemicals in two liquids. v. To come out of solution. precipitate KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions alter arrangements of atoms. reactant chemical reaction precipitate product catalyst 9.1 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME The masses of reactants and products are equal. SECTION OUTLINE SECTION OUTLINE coefficient law of conservation of mass 9.2 CHAPTER RESOURCES CHAPTER RESOURCES CALIFORNIA Content Standards 8.5.b Students know the idea of atoms explains the conservation of matter: In chemical reactions the number of atoms stays the same no matter how they are arranged, so their total mass stays the same.

VOCABULARY KEY CONCEPT CHAPTER HOME The masses of reactants and products are equal. SECTION OUTLINE SECTION OUTLINE coefficient law of conservation of mass Balanced chemical equations show the conservation of mass. Mass is conserved in chemical reactions. Chemical equations summarize chemical reactions. CH 4 O2O2 O2O2 ++ 2O 2 CH 4 + HO C H H H O O O CO 2 H2OH2OH2OH2O++ 2H 2 OCO 2 + H H H H O O O O C 9.2 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME A law stating that atoms are not created or destroyed in a chemical reaction. law of conservation of mass KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY The masses of reactants and products are equal. coefficient law of conservation of mass 9.2 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME Chemical reactions can be described by chemical equations. To write a chemical equation, you need to know three things: 1-the reactants and products in the reaction 2-The atomic symbols and chemical formulas of the reactants and products in the reaction 3-The direction of the reaction

VOCABULARY KEY CONCEPT CHAPTER HOME Chemical reactions can be described by chemical equations Example: The chemical equation for carbon combining with oxygen to form carbon dioxide is Reactants Products C + O  CO 2

VOCABULARY KEY CONCEPT CHAPTER HOME Chemical equations must be balanced. Balanced-an equal numbers of atoms on each side balance chemical equations by using coefficients Only coefficients can be changed to balance a chemical equation. Subscripts are part of the chemical formula for reactants or products and cannot be changed.

VOCABULARY KEY CONCEPT CHAPTER HOME The number before a chemical formula that indicates how many molecules are involved in a chemical reaction. coefficient KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY The masses of reactants and products are equal. coefficient law of conservation of mass 9.2 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME SECTION OUTLINE SECTION OUTLINE Chemical reactions involve energy changes. exothermic reaction bond energy endothermic reaction photosynthesis 9.3 CHAPTER RESOURCES CHAPTER RESOURCES CALIFORNIA Content Standards 8.5.c Students know chemical reactions usually liberate heat or absorb heat.

VOCABULARY KEY CONCEPT CHAPTER HOME SECTION OUTLINE SECTION OUTLINE Chemical reactions involve energy changes. exothermic reaction bond energy endothermic reaction In an endothermic reaction, more energy is added than released. Different bonds contain different amounts of energy. In an exothermic reaction, more energy is released than added. Exothermic Reactions Bond Energy Products (energy released) Reactants (energy added) Endothermic Reactions Bond Energy Products (energy released) Reactants (energy added) photosynthesis 9.3 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME The amount of energy in a chemical bond between atoms. bond energy KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions involve energy changes. exothermic reaction bond energy endothermic reaction photosynthesis 9.3 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME -A chemical reaction that releases energy. -Energy is released in an exothermic reaction, so energy is made one of the products. exothermic reaction KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions involve energy changes. exothermic reaction bond energy endothermic reaction photosynthesis 9.3 CHAPTER RESOURCES CHAPTER RESOURCES Exothermic Reactions Bond Energy Products (energy released) Reactants (energy added)

VOCABULARY KEY CONCEPT CHAPTER HOME -A chemical reaction that absorbs energy. -Energy is absorbed in an endothermic reaction, so it is made one of the reactants. endothermic reaction KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions involve energy changes. exothermic reaction bond energy endothermic reaction photosynthesis 9.3 CHAPTER RESOURCES CHAPTER RESOURCES Endothermic Reactions Bond Energy Products (energy released) Reactants (energy added)

VOCABULARY KEY CONCEPT CHAPTER HOME The process by which green plants and other producers use simple compounds and energy from light to make sugar, an energy-rich compound. This is an endothermic process in which light is absorbed and used to change carbon dioxide and water into glucose and oxygen. photosynthesis KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions involve energy changes. exothermic reaction bond energy endothermic reaction photosynthesis 9.3 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME SECTION OUTLINE SECTION OUTLINE Chemical reactions involve energy changes. exothermic reaction bond energy endothermic reaction In an endothermic reaction, more energy is added than released. Different bonds contain different amounts of energy. In an exothermic reaction, more energy is released than added. photosynthesis 9.3 VISUALIZATION View examples of endothermic and exothermic reactions. CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME

VOCABULARY KEY CONCEPT CHAPTER HOME

VOCABULARY KEY CONCEPT CHAPTER HOME I. Chemical reactions alter arrangements of atoms. A. Atoms interact in chemical reactions. B. Chemical reactions can be classified. KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions alter arrangements of atoms. C. The rates of chemical reactions can vary. 2. Surface Area 1. Concentration 3. Temperature reactant chemical reaction precipitate product catalyst 4. Catalysts 2. Chemical Changes 1. Physical Changes 3. Reactants and Products 4. Evidence of Chemical Reactions 9.1 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME II. The masses of reactants and products are equal. A. Careful observations led to the discovery of the conservation of mass. B. Chemical reactions can be described by chemical equations. KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY The masses of reactants and products are equal. 1. Balancing Chemical Equations 2. Using Coefficients to Balance Equations coefficient law of conservation of mass C. Chemical equations must be balanced. 3. Using the Conservation of Mass 9.2 CHAPTER RESOURCES CHAPTER RESOURCES

VOCABULARY KEY CONCEPT CHAPTER HOME III. Chemical reactions involve energy changes. A. Chemical reactions release or absorb energy. B. Exothermic reactions release energy. KEY CONCEPT SUMMARY KEY CONCEPT SUMMARY Chemical reactions involve energy changes. exothermic reaction bond energy endothermic reaction photosynthesis C. Endothermic reactions absorb energy. D. Exothermic and endothermic reactions work together to supply energy. 9.3 CHAPTER RESOURCES CHAPTER RESOURCES

CHAPTER HOME Image Gallery Click on the icons to see a larger image or animation. VISUALIZATION Observe how changing the concentration of a reactant can change the rate of a reaction. VISUALIZATION View examples of endothermic and exothermic reactions.

CHAPTER HOME Image Gallery BACK TO IMAGE GALLERY

CHAPTER HOME Image Gallery BACK TO IMAGE GALLERY

CHAPTER HOME Image Gallery BACK TO IMAGE GALLERY

CHAPTER HOME Image Gallery BACK TO IMAGE GALLERY

Chapter Resources CHAPTER HOME BACK TO CHAPTER Content Review Review key concepts and vocabulary Math Tutorial Review math concepts Resource Center Get more information on select science topics Standardized Test Practice Practice state standardized tests Animations Link to all the McDougal Littell Science animations Review Game Play a fun interactive review game Audio Readings Hear chapter audio readings Image Gallery Click here to review chapter images and animations Click on the items below to access resources on CLASSZONE.COM