The document explains the classification of matter and mixtures, including true solutions, colloidal solutions, and suspensions, along with their characteristics. It details the concept of pH and describes acids and bases as proton donors and acceptors, respectively. Additionally, it discusses buffer solutions, their mechanism of action, and the physiological buffer systems that help maintain pH stability in the body.

1. Matter Flowchart
Matter is any substance that has mass
and takes up space by having volume.
Can it be physically
separated?
Homogeneous
Mixture
(true solution)
Heterogeneous
Mixture Compound Element
MIXTURE PURE SUBSTANCE
yes no
Can it be chemically
decomposed?
no
yes
Is the composition
uniform?
no
yes
Colloids Suspensions
IPC-Solutions-Borders

2. Solution
• a mixture of two or more substances that is
composed of solutes and solvents
the substance in the smallest
amount and the one that
dissolves in the solvent
the substance in the larger
amount that dissolves the
solute
(solute) Water
(solvent)
(solution)

3. 1-True Solutions(crystalloids)
• Very small particle size: .01 nm-1 nm
• Are transparent
• Cannot be separated by filtration

4. 2- Colloidal soultions
• A heterogeneous mixture
• May or may not be transparent
• Medium particle size: 1 nm -200 nm
• Cannot be separated by filtration

5. 3- Suspensions
• A heterogeneous mixture
• Are not transparent
• Large particle size: over 200 nm
• Can be separated by filtration

6. pH
• pH is commonly expressed as –log[H+]
• the negative log (base10) of the
concentrations of hydrogen ions H+ in solution
• The pH scale

7. Acids and Bases
• An acid can be defined as a proton donor, a
chemical that increases the concentration of
hydrogen ions in solution.
• A base can be defined as a proton acceptor,
a chemical that reduces the concentration
of hydrogen ions in solution.

8. Buffers
• Definition: a solution that resists change in pH
following addition of strong acid or base.
– Typically a mixture of a weak acid with its salt of
strong base or a weak base with its salt of strong
acids.
– Can be adjusted to a particular pH value
• Why use them?

9. Mechanism of action of
buffers
9
On addition of a strong acid for example to
bicarbonate buffer, a neutral salt and weakly
dissociated acid are produced
HCl + NaHCO3 ↔ H2CO3 + NaCl
On addition of a strong base e.g NaOH to bicarbonate
buffer, weakly dissociated base and water are
produced
NaOH + H2CO3 ↔ NaHCO3 + H2O

10. Bicarbonate buffer
-
• HCO3 /H2CO3 = 20/1 when plasma
pH=7,4
• When hydrogen ion concentration increases
in plasma, HCO3
- ions bind H+ forming H2CO3.
• H2CO3 is converted to CO2 + H2O
• CO2 is released to atmosphere by lungs
10

11. Buffers
• The physiologic buffer systems present in various tissues and
body fluids function to keep the pH stable as enzymes act
only within a narrow pH range.
• Plasma buffers include:
• Bicarbonate buffer (NaHCO3/H2CO3) the most important
plasma buffer
• Phosphate buffer (Na2HPO4/NaH2PO4) )main buffer of urine)
• Plasma proteins (H protein/Na proteinate)
•