1. Activity Page # Chemical Change Lab 47
Date
Session #
Activity
Page #
11/7-8
Chemical Change Lab 47
11/8-9
Chemical Properties and Change Notes 48
Precipitate and pH Investigations 49
Homework:
Read 86D-91D
Answer ?’s: 1-6 on 91D
5, 11,19-21 on 102D

2. 8.P.1 Understand the physical properties of matter and changes that occur when matter interacts in an open or closed container 8.P.1.3 Compare physical changes such as size, shape and change of state to chemical changes that are a result of a chemical reaction to include changes in temperature, color, gas or formation of a precipitate.

3. Objective
TLW explain chemical changes by observing and making connections for several experimental trials then complete an exit ticket.

4. P48.
Notes Chemical change: a change that occurs that causes the chemical makeup (composition) of a substance to change. Chemical bonds are broken and new ones created
Evidence
Precipitate
Color change
Temperature change (Exothermic & Endothermic)
Gas produced
Other (Light produced, odor)
A chemical change is also called a chemical reaction

5. Chemical Changes Reactants  Products
Chemical changes occur when bonds between atoms are broken and new bonds created
Chemical changes result in the formation of NEW substances
Chemical changes/reactions are represented by an equation 
Reactants  Products
(input) (output)
(ingredients) (results)

6. Precipitate A precipitate is a solid
Two liquids, two gases, or a liquid and a gas are mixed together, one of the products is a solid

7. Color Change P 48 A true color change.
This is NOT dilution or concentration of color, or “color wheel” color change
(red + yellow=orange isn’t a color change)

8. P 48
Temperature Change
An increase or decrease in temperature. Two types:
Exothermic: temp increase
A + B  C + D + energy
Endothermic: temp decrease
A + B + energy  C + D

9. Gas Created Bubbles formed
P 48
Gas Created Bubbles formed

10. P 48
Other: light, odor…

11. Highlight evidence in each investigation
Highlight the evidence you recorded on your lab sheet that a chemical change occurred.

12. Notes (there’s more..)
Some chemical changes release energy…heat, light, etc. They get warmer. These are EXOTHERMIC
Some chemical changes absorb energy…they get colder. These are ENDOTHERMIC
Go back to your lab results. Note if the reaction was endothermic or exothermic. Not all reactions are endothermic or exothermic.

13. Precipitate Investigation
Send materials member
to the front for your
2 beakers of material
Pour the solution from
beaker 1 into beaker 2
Complete your data table
clean & return the beakers

14. Chemical Property
P 48
Properties that change the chemical nature of matter….chemical properties can only be observed or measured in a chemical reaction

15. Chemical Properties pH Reactivity Combustion/flammability Corrosion
Rusting (Iron)
Tarnishing (Silver, Copper, etc)

16. pH
A measurement of how acidic (1-6) or basic (8-14) a material is

18. Reactivity
How easily a substance reacts with other substances. (how easily it undergoes a chemical change)

19. Combustion/flammability
Rapid reaction with oxygen, always exothermic Reactant + Oxygen  Oxide(s) + H2O + heat/light C6H12O6 + O2  CO2 + H2O + energy

20. Corrosion
The gradual destruction (or deterioration) of a material as it reacts chemically with its environment. Corrosion is the primary means by which metals

21. Rusting
A type of corrosion. Iron forms Iron oxide (rust) when iron reacts with oxygen and water. This process gradually destroys the entire sample of iron.

22. Tarnish another type of corrosion
A thin layer of corrosion that forms over some metals. It only affects the outermost layer of the material. Unlike rust, the layer of tarnish seals and protects the underlying layers from reacting.
Copper tarnish
Silver tarnish

23. pH Investigation You will test the pH of 6 different substances.
To test pH:
dip the cotton swab
into the substance. Using
the cotton swab, “dot”
the pH paper with the
substance.
Match the color to the
pH scale and complete
your data table.