CH26 Electrolytes I - General Terms

Exam 4 Review: Chapter 26: Electrolytes I - General Terms

electrolyte - A substance which carries an electrochemical charge because its structure has unequal numbers of electrons and protons; all types of charged ions dissolved in body fluids.

monovalent - Describing an atom or molecule with one binding site available for bond formation or a charged ion carrying a charge of +1 or -1.

divalent - Describing an atom or molecule with two binding sites available for bond formation or a charged ion carrying a charge of +2 or -2.

cation - An ion or group of ions having a positive charge and, characteristically, attracting and having the potential to make ionic bonds with negatively charged anions; such positively charged ions move toward the negative electrode in electrolysis and electrophoresis.

anion - An ion or group of ions having a negative charge and, characteristically, attracting and having the potential to make ionic bonds with positively charged cations; such negatively charged ions move toward the positive electrode in electrolysis and electrophoresis.

nonelectrolyte - A substance which does not carry an electrochemical charge because its structure has equal numbers of electrons and protons; all types of uncharged solutes dissolved in body fluids.

percent concentration - A unit of measure of substances commonly used in clinical laboratory medicine; it measures mass per unit volume with the specific unit of milligrams/100 mL = mg/dL (deciliter).

milliequivalents - A unit of measure of electrolytes = charged ions commonly used in clinical laboratory medicine; it measures one-thousandth of an equivalent per unit volume; an equivalent represents the "hydrogen equivalence" when comparing the strength and bond forming relationships between acids and bases; this relationship is the mole (Avagadro's number of atoms or molecules) divided by the valence or Equivalent = Mole/Valence.

milliosmoles - A unit of measure of particles in solution commonly used in clinical laboratory medicine; it measures one-thousandth of an osmole per unit volume; an osmole represents the number of ions or particles into which a given substance dissociates when dissolved into solution; it is used when comparing the osmotic strength of different solutions, e.g., plasma and urine; this relationship is the molecular weight of the solute divided by the number of ions or particles into which a given substance dissociates or Osmole = Molecular Weight/Number of Ions or Particles. [Note: For example, one mole of glucose is also one osmole because glucose molecules do not dissociate into smaller particles in solution while one mole of sodium chloride is equal to two osmoles because salt dissociates into sodium and chloride ions: NaCL Û Na⁺ + Cl^-.

osmotic pressure - The hydrostatic force which can be generated when water moves across a selectively permeable membrane, following its concentration gradient, to a fluid compartment which is hypertonic to the compartment on the other side of the membrane. This force contributes to the overall size and shape of many cells.

osmolarity - The concentration of osmotically active particles in a solution expressed in terms of the Osmoles of solute particles per liter of solution; this measure is commonly used to quantify the tonicity or osmotic strength of solutions (isotonic/isosmotic; hypertonic/hyperosmotic; hypotonic/hyposmotic).

isotonic - An adjective describing any two solutions which have the same or equal osmotic pressure = osmotic strength.

[Reminder: There is another meaning for isotonic when applied to muscle contraction: isotonic contraction - The type of skeletal muscular contractions in which the force applied by the muscle is sufficient to move the load, and as a result, the muscle shortens while its muscle tension remains relatively constant.]

hypertonic - An adjective describing any solution which has the greater osmotic pressure = osmotic strength of two solutions being compared.

hypotonic - An adjective describing any solution which has the lesser osmotic pressure = osmotic strength of two solutions being compared.

Explain:

2. the terms percent, equivalents, and osmolarity in referring to the concentrations of solutions.

Term Definition Relevant Difference in Application

percent = percent concentration A unit of measure of substances commonly used in clinical laboratory medicine; it measures mass per unit volume with the specific unit of milligrams/100 mL = mg/dL (deciliter). A clinical unit of measure frequently applied to nonelectrolytes in body fluids. [Note: It may also be applied to electrolytes, if desired.] It refers to the concentration (mass per unit volume) of a particular single substance with the specific unit of milligrams/100 mL = mg/dL (deciliter). It acquired the nickname of "percent" because the mass measurement is in reference to a volume of one hundred milliliters of solution.

equivalent A unit of measure of electrolytes = charged ions commonly used in clinical laboratory medicine; an equivalent represents the "hydrogen equivalence" when comparing the strength and bond forming relationships between acids and bases; this relationship is the mole (Avagadro's number of atoms or molecules) divided by the valence or Equivalent = Mole/Valence. A clinical unit of measure frequently applied to electrolytes = charged ions and refers not to a concentration (mass per unit volume) of a particular single substance, but, rather, to a substance's "hydrogen equivalence" when comparing the strength and bond forming relationships between acids and bases; this relationship is the mole divided by the valence, i.e., an Equivalent = Mole/Valence.

osmolarity The concentration of osmotically active particles in a solution expressed in terms of the Osmoles of solute particles per liter of solution; this measure is commonly used to quantify the tonicity or osmotic strength of solutions (isotonic/isosmotic; hypertonic/hyperosmotic; hypotonic/hyposmotic). A clinical unit of measure frequently applied to the tonicity or osmotic strength of solutions (isotonic/isosmotic; hypertonic/hyperosmotic; hypotonic/hyposmotic) which refers to the combined presence or influence of all dissolved solutes in a solution rather than a measure of any particular single substance. The unit of measurement refers only to the number of particles per unit volume and indicates nothing about either the mass or the "hydrogen equivalence" (acid-base reactivity) of any of the solutes in the solution.

Term	Definition	Relevant Difference in Application
percent = percent concentration	A unit of measure of substances commonly used in clinical laboratory medicine; it measures mass per unit volume with the specific unit of milligrams/100 mL = mg/dL (deciliter).	A clinical unit of measure frequently applied to nonelectrolytes in body fluids. [Note: It may also be applied to electrolytes, if desired.] It refers to the concentration (mass per unit volume) of a particular single substance with the specific unit of milligrams/100 mL = mg/dL (deciliter). It acquired the nickname of "percent" because the mass measurement is in reference to a volume of one hundred milliliters of solution.
equivalent	A unit of measure of electrolytes = charged ions commonly used in clinical laboratory medicine; an equivalent represents the "hydrogen equivalence" when comparing the strength and bond forming relationships between acids and bases; this relationship is the mole (Avagadro's number of atoms or molecules) divided by the valence or Equivalent = Mole/Valence.	A clinical unit of measure frequently applied to electrolytes = charged ions and refers not to a concentration (mass per unit volume) of a particular single substance, but, rather, to a substance's "hydrogen equivalence" when comparing the strength and bond forming relationships between acids and bases; this relationship is the mole divided by the valence, i.e., an Equivalent = Mole/Valence.
osmolarity	The concentration of osmotically active particles in a solution expressed in terms of the Osmoles of solute particles per liter of solution; this measure is commonly used to quantify the tonicity or osmotic strength of solutions (isotonic/isosmotic; hypertonic/hyperosmotic; hypotonic/hyposmotic).	A clinical unit of measure frequently applied to the tonicity or osmotic strength of solutions (isotonic/isosmotic; hypertonic/hyperosmotic; hypotonic/hyposmotic) which refers to the combined presence or influence of all dissolved solutes in a solution rather than a measure of any particular single substance. The unit of measurement refers only to the number of particles per unit volume and indicates nothing about either the mass or the "hydrogen equivalence" (acid-base reactivity) of any of the solutes in the solution.