The document outlines topics to be covered in a biology class including identifying the properties of acids and bases, analyzing the pH scale and buffers, examining the parts of chemical reactions and enzymes, and determining the differences between the properties of water, ice, and solutions. Assignments are given focusing on vocabulary terms and questions related to these chemistry concepts.

1. Mr. Hunter Biology
10/18/2012
• Objective(s)
• SWBAT
• Identify the properties of an acid and a base
• Analyze the pH scale
• Determine the properties of buffers
• Analyze the parts of a chemical reaction and
enzymes
• Bell Ringer: How many more times acidic is stomach
acid than urine? Pg. 44 pH scale

2. Bell Ringer
Biology 10/17/2012
• What is causing the two
portions of the solution
not to mix together?
• Explain your answer.

3. Chemistry Overview and the Properties
of Water
Mr. Hunter
Biology
Kennedy High School
10/12/2011

4. • Matter: Anything that has
Nature of Matter mass and occupies space
• All matter is made of atoms
• Atom: The smallest unit of
matter that cannot be
broken down by chemical
processes.
• Parts of an atom: nucleus,
neutrons, protons and
electrons
• Question: What are the
major parts of an atom?

5. • Element: Substance made of
Nature of Matter one kind of atom – pure
substance
• Each element is represented by
a one or two letter symbol. Ex.
Na, Cl, He, H etc.
• Each element differs by the
number of protons in the atom.
• Electrons help to form chemical
bonds between atoms of
different elements
• Question: How do elements
differ from one another?
• Question: What are the
functions of electrons?

6. • Covalent Bonds: Sharing of electrons to
Nature of Matter and form a molecule such as water.
Chemical Bonds
• Hydrogen bonds: found in water
molecules. Shared electrons with
hydrogen and oxygen.
• Unequal sharing of electrons. Oxygen
pulls electrons more than other elements.
– Polar substance –found in water
• Ionic Bond: Bonds between atoms that
have gained or loss more than one
electron. Ex. Na+ and Cl- = NaCl
• Question: How are the electrons arranged
in polar substances?
• Question: What is the difference between
covalent bonds and ionic bonds?

7. • 70% of your body is water
Water and Properties
• Water is able to store heat
very efficiently. It can heat
very slowly and retain heat
longer than any other
substance.
• Heat can be released from
an object via water
evaporation.
• Question: How can an
organism lower its body
temperature?

8. • The atoms in liquid water
Water and Ice
and free to move around.
• The atoms of the elements
found in ice are rigid and
less dense than those
found in water.
• Therefore ice can float.
• Question: How do the
arrangement of molecules
in ice and liquid water
differ from each other?

9. • Water has a high heat
Temperature Moderation
capacity.
• Water can absorb or
release relatively large
amounts of heat with
only slight changes in
temperature.
• This property is due to
hydrogen bonding

10. Temperature Moderation
• Energy must be
absorbed to break
hydrogen bonds
• Energy is released as
heat when hydrogen
bonds are formed.
• Question(s): What must be
absorbed in order for hydrogen
bonds to break?
• What must be released when
hydrogen bonds form?

11. • Energy that water absorbs
Temperature Moderation
is initially used to break
hydrogen bonds between
molecules.
• When the bonds are
broken the energy
increases the molecular
motion of the molecules
which causes the
temperature of the water
to increase.

12. Temperature Moderation
• When the
temperature of water
drops, hydrogen
bonds reform, which
releases large
amounts of energy in
the form of heat.

13. • Cohesion: attraction
Water and Properties between substances of the
same kind. Ex: water
molecules are linked
together in this process. This
action forms surface tension
within water.
• Adhesion: Attraction
between different
substances. – Allows for the
process of capillary action
• Question: What is the
difference between cohesion
and adhesion?

14. CAPILLARY ACTION

15. • There is an equal distribution
Water and Polarity of charge within the water
molecule.
• Oxygen is electronegative – it
desires electrons.
• There is a greater negative
charge on the oxygen than
the hydrogen.
• Polar substances will dissolve
other polar substances and
some ionic compounds.
• Question: What does
electronegativity mean?

16. Review Questions
Cornell Format 10.16.12
• 1. Define matter.
• 2. Sketch an atom and identify its major parts.
• 3. How is an element different from an atom?
• 4. What part of the atom causes elements to
be different from one another?
• 5. How does water regulate heat?
• 6. Why does ice float?
• 7. What is the difference between a polar
substance and a nonpolar substance?

17. Concentrations and Solutions
• Solute: A substance which is
being dissolved.
• Solvent: Substance in which
the solute is dissolved in.
• Solution = Solute + Solvent.
Mixture in which one or
more substances are
uniformly distributed.
• Concentration: The amount
of solute dissolved in a fixed
amount of solution
• Water = universal solvent

18. Acid and Bases
• Water molecules can be
pulled apart.
• H20  OH- and H30+
• Hydroxide and Hydronium
• If the number (concentration)
of Hydronium ions is greater
than the number of
Hydroxide ions in solution,
then the solution is an acid.
• If the number of Hydroxide
ions is greater = base
• H30+ > = acid, OH- > = base

19. Acid and Bases
• The pH scale provides a
means for comparing relative
concentrations of hydroxide
and hydronium ions.
• The scale ranges from 0 to 14
• A pH of 0 is very acidic and a
pH of 14 is very basic.
• A pH of 7 is neutral. There is
an equal number of
Hydroxide and Hydronium
ions.

20. Acid and Bases
• A change in of one unit of the
pH scale represents a 10-fold
change in being acidic or
basic.
• Ex. Lemon juice is 10x more
acidic than orange juice.
• Ex. Orange juice is 1000x
more acidic than urine.

21. Buffers
• The control of pH is important in
living systems.
• Certain metabolic reactions in
the body can only function
within narrow pH ranges.
• Buffers: Chemical substances
Buffers
that neutralizes small amount of
acids or bases when added to a
solution.
• Buffering systems will maintain
normal pH values within the
body.

22. Chemical Reactions
• In a chemical reaction one or more
substances change to produce one or
more different substances.
• Two parts of the reaction are:
1. Reactants
2. Products
A+B  C+D
• Energy is required to move from
reactants to products.
• This is called the energy of activation
• Energy required to start the reaction.
• Catalysts/Enzymes speed up the rate
of reaction by decreasing the
activation energy.

23. Biology 10/18/2012
Assignment
• Cornell Format
• Vocabulary pg. 39
• Pg. 46 # 2,6,9,11,12,14,16