1. Chapter 2.2

2. Draw: H2 F2 CO2 CF4
Bell-ringer Practice

4. Now Draw Water

5. Polar Covalent Bond
Molecules have partial positive and partial negative charges (from unequal sharing of electrons)

6. Aattraction between slightly positive and slightly negative atom1.
Aattraction between slightly positive and slightly negative atom

7. Properties of Water High Specific Heat
Cohesion-attraction of molecules of a substance
Ex. Surface tension---water sticks to water
3. Adhesion-attraction of molecules of a different substance
Ex. Water sticks to windshield
Properties of Water

9. pH Scale Acids mix with water and release a Hydrogen ion.
Bases take a Hydrogen away , resulting in OH-
(Hydroxide)
pH Scale

10. Monday August 30 Draw a water molecule showing hydrogen bonds
List 3 properties of water
Lemon juice has pH=2—is it acidic or basic?
What is the difference in H+ ion concentration b/w lemon juice (pH=2) and tomato juice (pH=4)
Monday August 30
Warm-up

11. 2. Lemon Juice is acidic
3. Lemon juice has a H+ concentration 100 times greater than
Tomato juice.

12. Ch. 2 Chemisty of Life
2.4 Chemical Reactions

13. Bonds break during chemical reactions.
Chemical Reactions: process that changes substances into different substances by breaking and forming chemical bonds. EX: carbon dioxide and water vapor you breathe out is made by chemical reactions
Bonds break during chemical reactions.

14. Reactants, Products, & Bond Energy
Reactants: substances changed during a chemical reaction
Products: substances made by a chemical reaction
Example:
6CO2 +C6H12O CO2 + 6H2O
Reactants Products
Reactants, Products, & Bond Energy

15. Bond Energy: the amount of energy that will break a bond between two atoms. The same amount of energy is needed to break apart a bond as was used to form the bond.

16. Chemical Equilibrium Equilibrium = Balance
Many reactions move in both directions depending on the concentrations of the reactants/products
CO2 + H2O H2CO3
Equilibrium: when both the reactants and products are made at the same rate.
Chemical Equilibrium

17. Energy & Chemical Reactions
Activation Energy-the amount of energy that needs to be absorbed for a chemical reaction to start. Ex: pushing a rock up hill (see fig. 2.20)
Energy & Chemical Reactions

18. Endothermic Reaction Absorbs more energy than it releases
Total energy released

19. Releases more energy than it absorbs

20. Differenc between both…
Exothermic
Endothermic
Chemical reaction releasing more energy than it absorbs (the excess is often given off as heat or light)
Bond energy is lower in product
Ex. Cellular Respiration
Fireflies, Angler Fish, Squid
Chemical reaction absorbing more energy than it releases.
Bond energy is higher in product
Ex: Photosynthesis
Differenc between both…