Unit 5 Chapter 1Unit 5 Chapter 1

ReviewReview

When’sthe

Test?

1F – Describe the energy transfer during chemical reactions.1F – Describe the energy transfer during chemical reactions.

11. . Endothermic reactionsEndothermic reactions: : . . a. What is an a. What is an endothermicendothermic reaction? reaction?

Reactions that absorb ENERGY?

Endo (entering)

Thermic (heat)

Needs a continual input of energy or the reaction stops!

Which plant had NO continual input of energy?

Plant A

Plant B

1F – Describe the energy transfer during chemical reactions.1F – Describe the energy transfer during chemical reactions.

11. . Endothermic reactionsEndothermic reactions: : b. Which is greater in an b. Which is greater in an endothermic endothermic reaction reaction – the stored chemical energy (“SCE”) of the – the stored chemical energy (“SCE”) of the reactantsreactants or the stored chemical energy of the or the stored chemical energy of the productsproducts? Why?? Why?

The SCE of the products is greater than the The SCE of the products is greater than the SCE of the reactants. For energy to be SCE of the reactants. For energy to be conserved, energy is transferred INTO the conserved, energy is transferred INTO the system and the SCE of the system increases.system and the SCE of the system increases.

Which has more stored chemical energy? Reactants or Products?

1F – Describe the energy transfer during chemical reactions.1F – Describe the energy transfer during chemical reactions.

11. . Endothermic reactionsEndothermic reactions: : c. What change will occur in an c. What change will occur in an endothermicendothermic reaction?reaction?

In an endothermic reaction, energy is transferred In an endothermic reaction, energy is transferred into the system and the stored chemical energy into the system and the stored chemical energy of the system increases. of the system increases.

Observations include heat entering the system.Observations include heat entering the system.

1F – Describe the energy transfer during chemical reactions.1F – Describe the energy transfer during chemical reactions.

22. . Exothermic reactionsExothermic reactions: : a. What is an a. What is an exothermicexothermic reaction? reaction?

A chemical reaction that A chemical reaction that Produces energy.Produces energy.Exo – Exits or leavesExo – Exits or leavesThermic – heatThermic – heat Once the reaction is started by activation energy Once the reaction is started by activation energy

(like a spark or match) there is NO stopping (like a spark or match) there is NO stopping this type of reaction!this type of reaction!

The SCE of the The SCE of the reactantsreactants is greater than the is greater than the SCE of the SCE of the productsproducts. .

1F – Describe the energy transfer during chemical reactions.1F – Describe the energy transfer during chemical reactions.

22. . Exothermic reactionsExothermic reactions: : b. Which is greater in an b. Which is greater in an exothermicexothermic reaction – reaction –

the SCE of the the SCE of the reactantsreactants or the SCE of the or the SCE of the productsproducts? ? Why?Why?

Exothermic Reactant-Product Diagram

Which has more stored chemical energy? Reactants and Products?

1F – Describe the energy transfer during chemical reactions.1F – Describe the energy transfer during chemical reactions.

22. . Exothermic reactionsExothermic reactions: : c. What change will we observe in an c. What change will we observe in an exothermicexothermic reaction? reaction?

Energy is transferred out of the system and Energy is transferred out of the system and the SCE of the system decreases. the SCE of the system decreases. Observations include heat energy exiting Observations include heat energy exiting the system.the system.

1A – Identify chemical & physical interactions and support with evidence.1A – Identify chemical & physical interactions and support with evidence.

3. What is the difference between a 3. What is the difference between a physical physical interactioninteraction and a and a chemical interactionchemical interaction??

In a physical interaction the reactants and In a physical interaction the reactants and products don’t change. There is no evidence products don’t change. There is no evidence anything new has been created as in a anything new has been created as in a chemical interaction. chemical interaction.

A chemical interaction is any type of A chemical interaction is any type of interaction that results in at least ONE new interaction that results in at least ONE new material. material.

Which one of these is a physical interaction or chemical interaction?

Which one of these is a physical interaction or chemical interaction?

1A – Identify chemical & physical interactions and support with evidence.1A – Identify chemical & physical interactions and support with evidence.

4. What are some common chemical interactions 4. What are some common chemical interactions (reactions)?(reactions)?

Disappearance of one of the original materialsDisappearance of one of the original materials Appearance of a material in a different Appearance of a material in a different phase*phase* (at (at

room temperature) room temperature) Changes in other properties (like color, odor, texture, Changes in other properties (like color, odor, texture,

density, hardness, size or shape, interaction with density, hardness, size or shape, interaction with water (dissolve or doesn’t dissolve), flammability, water (dissolve or doesn’t dissolve), flammability, reaction with acid-base indicatorsreaction with acid-base indicators

*Phase means solid, liquid or gas*Phase means solid, liquid or gas

What do the circles mean?

What is he breathing into the bag?

These are ALL phases of matter

1B – Describe and classify materials according to their properties.1B – Describe and classify materials according to their properties.

5. Is one property of a material always enough to 5. Is one property of a material always enough to identify the material? Why or why not?identify the material? Why or why not?

No. Different materials are identified by a unique set No. Different materials are identified by a unique set of properties. Characteristics properties are more of properties. Characteristics properties are more useful for identifying unknown substances than useful for identifying unknown substances than properties like shape, mass, volume or texture. properties like shape, mass, volume or texture.

Characteristic properties like melting and boiling Characteristic properties like melting and boiling points and density. points and density.

1B– Dscribe and classify materials according to their properties.1B– Dscribe and classify materials according to their properties.

7. Use the Table of Density and Melting Point 7. Use the Table of Density and Melting Point and Boiling Point to describe the properties of and Boiling Point to describe the properties of a substance of your choosing.a substance of your choosing.

On your own

What is the freezing and melting point for water?

Why is this a characteristic property?

1C– Determine whether a substance is an acid, base, or neutral using physical & chemical properties. 1C– Determine whether a substance is an acid, base, or neutral using physical & chemical properties. Discuss strength based on the pH scale. .Discuss strength based on the pH scale. .

8. Describe a 8. Describe a neutralizationneutralization reaction. What are the reaction. What are the reactants? What are the products?reactants? What are the products?

Any reaction between an acid and a base is Any reaction between an acid and a base is called neutralization leaving a solution less called neutralization leaving a solution less acidic or basic than the original acid or base.acidic or basic than the original acid or base.

Reactants: Acid + BaseReactants: Acid + Base

Products: Salt + water Products: Salt + water

How would this happen?

1C– Determine whether a substance is an acid, base, or neutral using physical & chemical properties. 1C– Determine whether a substance is an acid, base, or neutral using physical & chemical properties. Discuss strength based on the pH scale. .Discuss strength based on the pH scale. .

9. How can you tell if something is an 9. How can you tell if something is an acidacid, , basebase, or , or neutralneutral??

Acid-base indicators are compounds (dye) that Acid-base indicators are compounds (dye) that change color in an acid, base, or both an acid change color in an acid, base, or both an acid or base. Ex: BTB or BTYor base. Ex: BTB or BTY

Look at their characteristic propertiesLook at their characteristic properties Hmmm..what are their characteristic Hmmm..what are their characteristic

properties?properties?

1C– Determine whether a substance is an acid, base, or neutral using physical & chemical properties. Discuss strength 1C– Determine whether a substance is an acid, base, or neutral using physical & chemical properties. Discuss strength based on the pH scale. .based on the pH scale. .

10. 10. How can you measure the How can you measure the pH number pH number of a of a substance?substance?

Specially coated paper called Specially coated paper called

Universal-coated paper or a pH meter will Universal-coated paper or a pH meter will measure the pH number on the scale.measure the pH number on the scale.

1C– Determine whether a substance is an acid, base, or neutral using physical & 1C– Determine whether a substance is an acid, base, or neutral using physical & chemical properties. Discuss strength based on the pH scale. .chemical properties. Discuss strength based on the pH scale. .

11. What are the pH numbers of 11. What are the pH numbers of acidsacids, , basesbases, and , and neutral substancesneutral substances??

1D– Identify the reactants and products in a chemical reaction. Describe the evidence for a chemical reaction. 1D– Identify the reactants and products in a chemical reaction. Describe the evidence for a chemical reaction.

12. What do the terms “12. What do the terms “reactantreactant” and “” and “productproduct” ” mean?mean?

Reactant: original materials in an interactionReactant: original materials in an interaction

Product: New materials created from an Product: New materials created from an interaction. interaction.

What would be the reactant and product in a burning candle?

1E– Give evidence to support the law of conservation of mass during chemical reactions .1E– Give evidence to support the law of conservation of mass during chemical reactions .

13. What is the 13. What is the Law of Conservation of MassLaw of Conservation of Mass??

The Law of Conservation* of Mass states The Law of Conservation* of Mass states that in a that in a closed mass systemclosed mass system (a system with (a system with no mass inputs and mass outputs) the mass no mass inputs and mass outputs) the mass of the system does not change during of the system does not change during interactions.interactions.

*What does it mean to conserve something?

1E– Give evidence to support the law of conservation of mass during chemical reactions .1E– Give evidence to support the law of conservation of mass during chemical reactions .

14. What is a 14. What is a closed systemclosed system and how does it relate to and how does it relate to the law?the law?

A A closed mass systemclosed mass system (a system with no mass (a system with no mass inputs and mass outputs) the mass of the inputs and mass outputs) the mass of the system does not change during interactions.system does not change during interactions.

Is a tree planted outside in an open or closed system? Why?

The EndThe End Study your lab notebookStudy your lab notebook Study your Activity SummariesStudy your Activity Summaries Study quizzesStudy quizzes Study!!!Study!!! When is the test?When is the test?