unit 7, chapter 20
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Unit 7, Chapter 20. Integrated Science. Unit Seven: Changes in Matter. Chapter 20 Chemical Reactions. 20.1 Chemical Changes 20.2 Chemical Equations 20.3 Conservation of Mass 20.4 Using Equations as Recipes. Chapter 20 Learning Goals. - PowerPoint PPT PresentationTRANSCRIPT
Unit 7, Chapter 20
Integrated Science
Unit Seven: Changes in Matter
20.1 Chemical Changes
20.2 Chemical Equations
20.3 Conservation of Mass
20.4 Using Equations as Recipes
Chapter 20 Chemical Reactions
Chapter 20 Learning Goals Distinguish between physical and chemical changes in matter
using examples from everyday life. Write and balance chemical equations. Investigate and identify the law of conservation of mass. Use chemical equations to predict the amount of product that will
be produced in a reaction. Design an experiment to prove conservation of mass. Identify the mathematical relationship between the mass in grams
of reactants and products, the coefficients in a balanced equation, and the formula masses of the reactants and products.
Identify economic and environmental reasons for recycling tires.
Chapter 20 Vocabulary Terms excess reactant
hydrochloric acid product
limiting reactant
reactant
percent yield
physical change
balance
chemical change
chemical equation
chemical reaction
coefficient
conservation of mass
20.1 Chemical ChangesKey Question: What is the evidence that a chemical change has
occurred?
*Read text section 20.1 AFTER Investigation
20.1
20.1 Chemical ChangesWe can classify changes in matter as either
chemical changes or physical changes.
The process of digestion involves both physical and chemical changes to the food.
20.1 Chemical ChangesEvidence of chemical change:
— bubbling (formation of gas)— turning cloudy (formation of a new solid)— temperature change (heat or light released)— color change (formation of a new solid)
20.2 Chemical EquationsKey Question: How do you balance
chemical equations?
*Read text section 20.2 AFTER Investigation 20.2
20.2 Chemical Equations Numbers and types of atoms must balance
20.3 Conservation of Mass Antoine Laurent Lavoisier
(1743-94), established an important principal based on his experiments with chemical reactions.
The total mass of the products of a reaction is equal to the total mass of the reactants.
This is known as the law of conservation of mass.
20.3 Conservation of MassKey Question: How can you prove that mass is conserved in a
reaction?
*Read text section 20.3 BEFORE Investigation 20.3
20.4 Using Equations as RecipesRecipe #1: Chocolate Cake Recipe
1 cup flour1/2 cup cocoa
powder1/2 cup butter1 tsp vanilla1 cup sugar
1 teaspoon baking powder1/2 cup milk
1 eggIn a bowl, combine flour, sugar, cocoa powder, and baking power. Add butter, milk, vanilla, and egg. Mix until smooth. Bake in a 350°F oven for 35 minutes. Makes 8 servings
20.4 Using Equations as RecipesRecipe #2: Water
2 molecules of hydrogen gas1 molecule of oxygen gas
Combine the molecules in a closed container. Add a spark of electricity. Makes two molecules of water.
20.4 Using Equations as Recipes
Balanced equations show how mass and atoms are conserved.
20.4 Using Equations as Recipes
20.4 Using EquationsKey Question: How can you predict the amount of product in a
reaction?
*Read text section 20.4 BEFORE Investigation 20.4