PhyChem 2 Midterm Exam Flashcards
Mixtures for which the solute obeys Henry’s law and the solvent obeys Raoult’s law are called ___________________.
ideal-dilute solutions
The ratio of the partial vapour
pressure of each component to its vapour pressure as a pure liquid, pA/p*A, is approximately equal to the mole fraction of A in the liquid mixture.
Raoult’s law
for real solutions at low concentrations, although the vapour pressure of the solute is proportional to its mole fraction, the constant of proportionality is not the vapour pressure of the pure substance.
Henry’s Law
A ________________ depends only on the number of solute particles present, not
their identity.
colligative property
Enumerate the colligative properties.
(a) elevation of boiling point
(b) depression of the freezing point
(c) solubility
(d) osmosis
(from the Greek word for ‘push’) is the spontaneous passage of a pure solvent into a solution separated from it by a semipermeable membrane
osmosis
The _____________ theory ascribes deviations from ideality to the Coulombic interaction of an ion with the ionic atmosphere that assembles around it.
Debye–Hückel
delta G<0, (exergonic) the forward reaction is
spontaneous
delta G>0, (endergonic) reverse reaction is
spontaneous
delta G=0, reaction is
equilibrium
A system at equilibrium, when subjected to a disturbance, responds in a way that tends to minimize the effect of the disturbance
Le Chatelier’s principle
__________________ is an expression for the slope of a plot of the equilibrium constant (specifically, ln K) as a function of
temperature
van’t Hoff equation
E* is also known as the ______________.
standard electrode potential
Oxidation is ________ of electrons.
loss
Reduction is ________ of electrons.
gain
Oxidation and reduction occur __________.
simultaneously
Oxidation results in an ________ in oxidation number.
increase
Reduction results in an ________in oxidation number.
decrease
Zn to Zn+2 is ____________ because___________.
oxidation because the O.N increases from 0 to +2
H+ to H is ____________ because_________________.
reduction because the O.N decreases from +1 to 0.
If delta G<0 then the reaction is ___________.
spontaneous
a _________________ uses a spontaneous redox reaction to generate electrical energy.
voltaic cell
a ________________ uses electrical energy to drive a nonspontaneous reaction.
electrolytic cell
delta G>0 then the reaction is _________.
nonspontaneous
Electrochemical cells are constructed using 2 main components ____________ and ____________ solution.
electrolyte and electrode
The electrode at which oxidation occurs.
anode
The electrode at which reduction occurs.
cathode
It is a cell where energy is released from a spontaneous redox reaction.
voltaic cell
It is a cell where energy is absorbed to drive a nonspontaneous redox reaction.
electrolytic cell
electrons flow from __________ to ______________.
anode to cathode
half cells are connected by the external circuit that is called ___________.
salt bridge
Anode is the __________ electrode in a voltaic cell.
negative
Cathode is the __________ electrode in a voltaic cell.
positive
Salt bridge allows ________ to flow through both half cells.
ions
The salt bridge maintains ___________ __________ by allowing excess Zn2+ ions to enter from the anode, and excess negative ions enter from the cathode.
electrical neutrality
A salt bridge contains ____________ cations and anions often K+ and NO3-; dissolved in a gel.
nonreacting
_____________ electrode is a component in its half cell and is a reactant or product in the overall reaction.
active
_____________ electrode provides a surface for the reaction and completes the circuit. It does not participate actively in the overall reaction.
inactive
Name 2 examples of common inactive electrodes.
Platinum and graphite
Anode components are written on the _________________.
left
Cathode components are written on the _________________.
right
double line in a cell notation means ____________.
half cells are physically separated.
the single line shows a _________ between the components of a half cell.
phase boundary
a comma is used to show that _____________.
components are in the same phase.
It depends on the difference in electrical potential between the two electrodes.
cell potential
the cell potential is also known as the _______________ or ____________________.
voltage of the cell or the electromotive forces (emf)
The ______________ is designated Ecell and is measured at a specific temperature with no current flowing and all components in their standard states.
Standard Cell Potential
Ecell is equal to (write the formula)
Ecell= cathode minus anode
___________________ has a standard electrode potential defined as 0.
Standard Hydrogen Electrode
potential rises due to a chemical reaction occurring in the cell
Chemical cell
potential rises due to a concentration difference, resulting in transfer of matter.
Concentration cell
