UNIT 2 Flashcards
Ionization
Breakdown of electrolyte molecules into small constituent ions.
Example Ionization:
NaCl –> Na+ + Cl-
Electrolytes
Molecules split or dissociate into electrically charged atoms (ions). Carries an electrical current when in solution. Compounds in body are weak electrolytes.
Example: Na, K, Cl, CO2.
Ions
Atom or group of atoms that carry electrical charge. Gain or loss of electrons.
Cation
Ion with positive charge. Example: Na+ and K+.
Anion
Ion with negative charge. Example Cl-.
Anode
negative charge
Cathode
positive charge.
Acid
Hydrogen ion donor.
Strong Acids
Give off high concentration of H+ in H2O.
Examples: HCl, H2SO4.
Weak Acids
Give off low concentration of H+ in H2O.
Examples: H2CO3, CH3COOH.
Base
Hydrogen ion acceptor. hydroxyl ion donor.
Salt
metal or ammonium ion electrovalently joined to anion other than hydroxyl. To produce a salt an acid reacts with a base.
Example of a salt producing:
HCl + NaOH —> NaCl + H2O.
Normal Salt
Complete replacement of H+.
Example: NaCl.
Acid Salt
Partial replacement of H+.
Example: NaHCO3.
Alkaline salt
Partial replacement of OH-.
Weak Electrolyte Characteristics
Small portion of molecules dissociate, remainder do not.
Equilibrium maintained between molecules and ions
Product of molar concentration of ions divided by molar concentration of undissociated molecules is a constant value (Dissocation Constant K).
Dissociation of K Example: Formula
H2CO3 –> H+ + HCO3-
K= [H+] x [HCO3-]/[H2CO3]
Information needed to calculate K
Concentration of solution (M)
Amount of dissociation (%)
Dissociation of K of H2O
K= [H+] x [OH-]/[H2O]
[H+]= 3.0 x 10-8 M/L
Acid or Base?
Base
[H+] greater than H2O (1.0 x 10-7) solution is….
acidic
[H+] less than H2O (1.0 x 10-7) solution is…
basic.
[H+] =1.0 x 10-6 M/L is…
Acidic
[H+]= 4.0 x 10-7 solution is…
Acidic
Nanomole
one billionth of a mole. (10-9)
pH
logarithm of reciprocal of molar hydrogen ion concentration.
pH=log101/[H+]
pH=-log[H+]
pH and [H+] are inversely related
H+ ion goes up, the pH goes down. (vice versa).
Water is…
neutral
pH scale range is..
0-14
pH less than 7 is..
acidic
pH greater than 7 is…
basic
Diffusion
Process by which solute (gas/solid) in solution moves. Molecules or ions diffuse from an area of higher concentration to lower.
When will diffusion occur?
It will occur across a membrane if membrane is permeable to substance. Move without restriction.
Osmosis
Movement of solvent (H2O) through semipermeable membrane. Moves to area where there is a higher concentration that cannot pass through membrane.
H2O moves from an area where ther is ____ amount of H2O in relation to solute to an area where there is ___ H2O in relation to solute.
greater, less
Osmotic Pressure
More concentrated solution on one side of semipermeable membrane and less concentrated solution on other side. A force that pulls water through membrane to the more concentrated side. (Side with more solute).
Tonicity
Relative degree of osmotic pressure exerted by a solution.
Three levels of tonicity
Isotonic, hypotonic, and hypertonic.