Solutions, Colloids, and Suspensions Flashcards
A stable mixture of two or more substances that cannot be separated using a centrifuge.
Solution
A substance that dissolves in a solvent.
Solute
What are the 3 ways substances and particles combine with water?
Colloids, suspensions, solutions
The medium in which a solute dissolves.
Solvent
What is considered the universal solvent?
Water
What are the 3 basic types of physiologic solutions?
ionic, polar covalent, nonpolar covalent,
An example of an ionic (electrovalent) solution is?
saline solution (0.9% NaCl)
An example of a polar covalent solution is?
Hydrochloric acid (HCl), Acetic acid (CH3COOH)
An example of a nonpolar covalent solution is?
Glucose (C6H12O6)
A solution in which a solute dissociates into ions is called?
electrolyte solution
cations
positive ions that migrate to a cathode
anions
negative ions that migrate to an anode
Nonelectrolytes
nonpolar covalent solutions where the solute remains intact and does not carry a positive or negative charge
colloids (dispersions/gels)
consist of large molecules that attract and hold water; example=protoplasm inside cells
hydrophilic
water loving
hypotonic
having a lower concentration of electrolytes than body plasma
Suspensions
composed of larger particles that float within a liquid; capable of separation with a centrifuge; example=RBCs in plasma
solubility
the ease with which a solute dissolves in a solvent
What are the 5 factors that influence solubility
- nature of the solute
- nature of the solvent
- temperature
- pressure
- concentration
how does temperature affect solubility?
more gas dissolves in a liquid at lower temperatures; as temp increases the gas comes out of solution
Henry’s Law
describes the effect of pressure on solubility of a gas in a liquid; as pressure increases, more gas dissolves as the pressure increases
concentration
the amount of solute dissolved into the solvent
example of qualitative description of a solution
dilute
example of quantitative description of a solution
50 mL of 4.0 M solution
dilute solution
small amount of solute relative to the solvent
saturated solution
solvent cannot dissolve anymore solute; additional solute would just settle to the bottom
supersaturated solution
a solution where the solvent contains more solute than a saturated solution at the same temperature and pressure
What are the Starling forces?
The four separate forces (2 hydrostatic, 2 colloid) driving fluid filtration across a capillary wall
According to the Starling forces, if the net result of fluid transfer across a membrane is positive, that means what?
fluid from the capillary moves into the interstitium
According to the Starling forces, if the net result of fluid transfer across a membrane is negative, that means what?
Fluid will be reabsorbed from the insterstitium back into the capillary.
What is the most important physiologic characteristic of solutions within the body?
Their ability to exert pressure.
What is osmotic/oncotic pressure?
the minimum pressure that must be applied to a solution to halt the flow of solvent particles through a semipermeable membrane
What is a semipermeable membrane?
a membrane that permits passage of solvent molecules but not solute; example=capillary wall
How can osmotic pressure be measured?
by connecting a pressure manometer to the expanding side of the semipermeable membrane
What is osmolality?
the ratio of solute to solvent (water)
What is tonicity?
the relative concentrations of solutions that determine the direction and extent of diffusion and is influenced by the amount of solute that cannot cross the membrane
What is the tonicity of body cellular fluid?
0.9%
What does isotonic mean?
solutions with the same tonicity; physiologically, this would be 0.9% saline solution and body cellular fluid
What does hypertonic mean?
more tonicity (more oncotic pressure and higher concentration due to less water); example=sputum induction 3-7% saline
What does hypotonic mean?
less tonicity (less oncotic pressure and lower concentration due to more water)
What is turgor?
the pressure inside a cell that counteracts osmotic pressure
2 ways to quantify the amount of solute in a solution
- weight (mg or g)
- electronegativity (chemical combining power, Na+ or HCO3-)
What are equivalent weights?
Amounts of substances that have equal chemical combining power (gEq and mEq)
1 gEq=? mEq
0.001 gEq
What is valence?
the number of electrons that need to be added or removed to make a substance electrically neutral
How do you calculate gram equivalent weights?
gEq=gram molecular weight/valence
Example= Fe3+ has an atomic weight of 55.8
so 55.8/3=18.6 g
How do you calculate the gEq of an acid?
gEq of an acid=gram molecular weight of the acid/ the number of replaceable hydrogen atoms
How do you calculate the gEq of a base?
gEq of a base=gram molecular weight/the number of OH- groups
How do you convert gram weight to gEq?
gEq=gram weights/gEq
Example=58.5 g NaCl/gEq 58.5 g=1 gEq
How do you convert gEq to milliequivalent weights?
mEq=gEq/1000
How do you convert mg/dl to mEq/L?
mEq/L=(mg/dl x 10)/equivalent weight
What are the 6 methods to quantify the amount of solute in solution?
- ratio solution
- weight per volume solution
- percent solutions
- Molal solutions
- molar solutions
- normal solutions
What is the dilution equation?
V1C1=V2C2
Dilute 10 mL of a 2% solution to a concentration of 0.5%.
V2=(10 mL x 0.02)/0.005
V2=40 mL