Fundamental Physical and Chemical Concepts

Question 1

Molarity

Equivalence

Weight/vol

Answer 1

Amount of substance relative to gram molecular weight

Stoichiometry between cations and anions…determined by valence of ions

mEq = mM concentration times charge

Question 2

Osmosis and osmotic pressure

Answer 2

Movement of H2O across membranes

Osmotic pressure is the DRIVING force for movement of H2O across membranes…also the force that must be applied to stop osmotic H2O flu

Question 3

Osmolarity and osmolality

Answer 3

Osmolarity - solute conctration*# of dissciablew particles

Osmolality - number of solute particles per kilogram of solvent…this is tempertautre independent**

Question 4

Tonicity

Answer 4

Determined by effect on volume of exposed cells

If cell volumes increases (outside less water than in) - hypotonic

Question 5

Urea

Answer 5

Reflection coefficient is not 1 so even if concentrations are the same, it could appear as a hypotonic solution

Question 6

Electrochemical equilibrium

Answer 6

The chemical and electrical properties must be at equilibirum…if one of these changes, the other one changes as well