1. It’s Lab Day! Think back to middle school physical science class
Read each statement and identify it as an example of a physical or chemical change.
Chopping wood
Dissolving salt in water
Cooking egg white
A juice box in the freezer
Gasoline is ignited
Jewelry tarnishes
Think back to middle school physical science class

2. Write a definition of a physical and a chemical change.

3. Chemical Reaction 6CO2 + 6 H2O  C6H12O6 + O2
Illustrate how old substances become new substances.
Old substances are called reactants.
New substances are called products.
A chemical reaction uses an arrow to indicate the change. It is read as ‘yields’.
6CO2 + 6 H2O  C6H12O6 + O2
Photosynthesis!!!!

4. Chemical Reactions Lab
Safety Procedures
Wear goggles at all time!!!
Do not touch any liquid in the beaker
If you spill a liquid, call teacher.
Wash glassware with the special soap and brush. Dry with towel.
Keep work area neat.

5. Reactants for Today’s Chemical Reactions+
Reaction #2
water

6. Materials:
Spatula
Weigh boat
Glass stirring rod
beaker
Graduated cylinder

7. How to Use a Balance Press the Tare or Zero Button.
When you see a 0.00 g reading, place weigh boat on the balance.
Press the Tare or Zero Button again.
When you see a 0.00 g reading, begin adding the baking soda until you read 2.0 g
Carefully carry the baking soda back to lab.

8. Clean Up Procedure
Baking Soda
Calcium chloride
Throw out weigh boat in trash
Run water in sink and pour the dissolved baking soda down the drain.
Use soap and brush to wash the beaker and stirring rod.
Using wet paper towel, wipe off temperature sensor.
Throw out weigh boat in bin of water.
Gently wipe off the thermometer with a damp paper towel
Run water in sink and pour the dissolved calcium chloride down the drain. Be careful, it may be hot.
Wash your hands.
Return thermometer and ring stand setup to the table.
Return glassware to cart.
After cleanup, complete all data tables and analysis questions.

9. This graph is depicting the changes in temperature during an exergonic and endergonic reaction.
Key:
Red – Endothemic
Blue –Exothermic

10. Test your understanding of the Chemical Reactions Lab which you ran during the lab period. Can you explain to someone what each column represents?

11. Illustrating an Exergonic and Endergonic Reaction
Creating an Energy Diagram

12. Exothermic Reaction – Energy Reactants contain is more than
the energy the products contain.
Reactants
Temp of surrounding
Is increasing
“Amount” of
energy
released
Energy being
Released into surroundings
Free energy
Products
Progress of the reaction
Exothermic Reaction: Energy from the reactants is released
during the chemical reaction so the products have less energy.

13. Progress of the reaction
Endothermic Reaction – Energy Reactants contain is less than
the energy the products contain.
Temp of surrounding
decreasing
Products
“Amount” of
energy
absorbed
Energy being
Absorbed from
surrounding
Free energy
Reactants
Progress of the reaction
Endothermic Reaction: The reactants absorb energy from the surroundings
during the chemical reaction so the products have more energy than the
reactants.

14. Important Points:
A chemical reaction forms new substances called products.
A chemical reaction when forming products can either be exothermic or endothermic.
When calcium chloride and water reacted, it released heat and the surrounding temperature went up.
The chemical reaction of calcium chloride and water is an exothermic reaction. The data collected that supported this is that the temperature went up.
The chemical reaction of baking soda and vinegar is an endothermic reaction. The data that indicated this was that the temperature went down.
The reactants baking soda and vinegar has less energy than the products of this reactions.
The reactants of the calcium chloride and water reaction have more energy than the products of this reaction.

15. For each picture, write (4) descriptive statements.
Which part in each diagram represents the energy that will be or is being used to do work?
Cellular Work Examples: