DAVIS Flashcards
a chemical bond
formed by electrostatic attraction between positive and negative ions
ionic bond
formed by the sharing of a pair of electrons between atoms
covalent bond
usually weakly attractive, forces that can hold molecules together
intermolecular forces
include both
dipole–dipole interactions and dispersion forces;
weak, short-range
attractive forces between neutral molecules
Van der Waals Forces
an electrically charged atom or molecule
ion
A solution of calcium chloride is prepared in a 1.00-L volumetric flask. A 60.00-g sample of
CaCl2 is added to a small amount of water in the flask, and then additional water is added to bring
the total volume of solution to 1.00 L. What is the concentration of calcium chloride in units of
molarity?
0.5406 mol/L
symbolic representation of a chemical reaction in terms of
chemical formulas.
chemical equation
The phase-change reaction by which dissolved
chemicals form insoluble solids is called
precipitation reaction
opposite of precipitation reaction
dissolution reaction
it can act as either an acid
or a base
amphoteric
occur in natural waters whenever the “coordination”
of two (or more) atoms, molecules, or ions results in the formation of a more stable
product
complexation reactions
The Lewis bases attached to the metal atom
in a complex are known as
ligands
At this point the rate of the
reaction proceeding to the right equals that proceeding to the left.
chemical equilibrium
states that the value of the equilibrium
constant expression K is a constant for a particular reaction at a given temperature, and that this
value is independent of the equilibrium concentrations of the chemicals substituted into the
equation.
law of mass action
The tendency (or
driving force) for a reaction to reach equilibrium is driven by the
Gibbs Free Energy
The relationship between the equilibrium constant, K, and deltaG◦
deltaG° = −RT ln K
The degree of ionization of water is very small and can be measured by what is called the
dissociation (or ionization) constant of water, Kw
acids that do not completely dissociate in water.
weak acids
An equilibrium constant exists that relates the degree of dissociation to the equilibrium constant
for that reaction:
Ka = [H+][A−]/[HA]
derived from thermodynamic data and
can be determined from the change in Gibbs free energy* for the reaction.
solubility products
Reactions that take place in a single phase
homogeneous reactions
Those that occur at surfaces between
phases
heterogeneous reactions
Some alkanes (and other organic compounds) may have the same molecular
formula but different structures.
structural isomers
are cyclic and have alternating double bonds, in a resonance structure in
which all of the carbons in the ring share the -bond electrons
aromatic compounds
In ______________, either the liquid or the substance itself is changed from a liquid phase to a gas
phase in order to achieve separation.
distillation
In ________________ the substance in the liquid phase combines with another chemical to form a
solid phase, thus achieving separation from the water.
precipitation
involves a phase change, wherein the dissolved substance attaches to the
surface of solid particles.
adsorption
can separate a substance from water or a solid by extracting it into another
liquid, hence a phase change from water to a different liquid
Liquid Extraction
Suspended particles can range up to about in size.
100 micrometers
are usually defined on the basis of size and are generally from 0.001 to
about 1 micrometer in size.
colloidal particles
A solution that resists large changes in pH when an acid or base is added or when the solution
is diluted
buffer
the ability of a water to resist changes in
pH when an acid or base is added.
buffering capacity
describe a water’s ability to resist changes in pH on the
addition of acid
alkalinity (acid-neutralizing capacity)
describes the
ability of a water to resist changes in pH due to the addition of base
acidity (base-neutralizing capacity)
defined as the sum of all titratable bases to a pH of approximately 4.5. It
alkalinity
