Water Pt.2 Flashcards
Bronsted-Lowry Acid
Proton donor
Bronsted-Lowry Base
Proton acceptor
The exact point at which the titrant reacts completely with the analyte is the equivalence point
the equivalence point (stoichiometric point)
Freezing point depression
drop in the max. temp at which a substance freezes
Freezing point is easily seen when comparing
pure water and solution freezing temps
Boiling point elevation is a result of an increase in the
concentration of a solution when compared to pure water
P (Vapor pressure in cmpd/soln) =
(P*)(X)
P*: vapor pressure of volatile cmpd at a certain temp
X : mile fraction of cmpd
Raoult’s Law
P(soln) = (Xsol)(P*sol)
P(soln) = solu vapor pressure
Xsol = mole frac. of sol
P* sol = vapor pressure of pure solvent
p/p* =
Aw (water activity)
p = vapor pressure of pure water
p* = vapor pressure of water in food
%ERH/100
Aw (water activity)
Hydration
combined with water to form a hydrate with the water molecule retained in its molecular state
Dehydration
process of removing water from a substance or compound
Solvent Properties
capable of dissolving another substance without changing chemical form
Solution
Physically and homogenous mixture in which the solute is either in an ionic or molecular state of subdivision
Hydrolysis
decomposition of a chemical compound by reaction with water
If separated from pure water by a semi-permeable membrane water molecules will
pass through the membrane to equalize the concentration (OSMOSIS)
Isotonic solutions refer to
two solutions that have equal osmotic pressure
Colloids =
mixtures with solid, liquid, or gas suspended (dissolved) in a liquid
M1 V1 =
M2 V2
Equilibrium constant for water: Keq
[H+][OH-]/[H2O]
Living cells have a VERY
narrow range of tolerance for pH i.e. [H+]
Water Activity (definition)
ratio of the partial pressure of water in a sample (p) and the vapor pressure of pure water (p0) at the same temperature
Utilization of water for food processing
+ Soaking
+ Cleaning
+ Blanching
+ Chilling
+ Cooling
+ Sanitizing
