Electrochemistry and Colligative properties

Question 1

in electrochemistry, the goal is to get __ ___ out of __ __ or vice versa

Answer 1

electrical work, chemical reaction

Question 2

Electrical work is one type of _____ work. In a process at constant pressure and temperature, the maximum non-expansion work that can be extracted from a system in a ___ __ is equal to the change in __ __ by this process.

Answer 2

non-expansion, reversible process, gibbs energy

Question 3

a cell that produces electricity as a result of a spontaneous chemical reaction in the cell

Answer 3

galvanic cell

Question 4

a cell who’s reaction is driven by an external source of current from humans

Answer 4

electrolytic cell

Question 5

The ___ is where oxidation takes place, and the ___ is where the reduction takes place. The reaction at the ___ always appears at the left.

Answer 5

anode, cathode, anode

Question 6

The ___ equation gives a relation between the electromotive force and the __ ___ in the cell. Ecell and Ecell° are both ___, being independent of the ____ chosen for the cell reaction

Answer 6

nernst, actual concentration, intensive, size

Question 7

The __ ___ electrode potential is set to be 0 at all temperatures, and the reaction is ______. The standard electrode potential of an electrode is the emf measured for a cell where the ___ electrode is the standard hydrogen electrode, and the ___ is the one in question with all components in their standard states.

Answer 7

standard hydrogen, 2H+ + 2e –> H2, left, right

Question 8

To calculate the emf of a total reaction, it is the ____ - ____, where the right hand side is the more _____ and greater magnitude ___ ___

Answer 8

rhs, lhs, positive, reduction potential

Question 9

For a spontaneous cell, the ecell is ___, while if the backwards reaction is spontaneous the ecell is ____. Ecell is __ at equilibrium

Answer 9

positive, negative, 0

Question 10

For a whole cell reaction, to calculate the total ecell, calculate the ecell of each cell separately using its ______ __ ___, and taking into account the number of _____ in each reaction. Then it is ______ -_____. In the standard emf, the amount of ___ is not included in the equation

Answer 10

standard reduction potentials, electrons, rhs, lhs, electrons

Question 11

In a half reaction, the standard emf and emf need to be calculated from the _______ ____ ____

Answer 11

gibbs free energy

Question 12

The effect of a solute is to ____ the boiling point of a solvent and to ___ its freezing point.

Answer 12

raise, lower

Question 13

bB is the ___ of the solute, in other words, the ____ of solute / ____ of solvent

Answer 13

molality, moles, kg

Question 14

Kb is the _____ constant and it depends on the type of solvent only. It is equal to ____/____

Answer 14

ebullioscopic, MRTb^2/Hvap

Question 15

Kf is the ____ constant and it depends on the type of solvent only. it is equal to ____/___

Answer 15

MRTf^2/Hfus

Question 16

Colligative properties like the elevation. of the boiling point and depression of the freezing point depend only on the ____ of solute particles and not on the ___ of solute molecules

Answer 16

number, identity

Question 17

Xb is the mole fraction of the solute, in other words, the number of moles of the ____ over the number of moles of the ____. Or the number of moles of the solute over (___/___)

Answer 17

solute, solvent, mass(solvent)/Mw(solvent)

Question 18

The flow of pure solvent through a semipermeable membrane into a more concentrated solution

Answer 18

osmosis

Question 19

The pressure that must be applied to the concentrated solution to stop the inward flow of solvent

Answer 19

osmotic pressure

Question 20

In an ___ environment, the amount of ions in and out of the cell are the same. In a ____ environment, there are more solutes in the cell, and water will enter the cell, and it will ___. In a _____ environment, there are less solutes inside the cell and water will flow out of the cell, making it ____

Answer 20

isotonic, hypotonic, lyse, hypertonic, shrivel

Question 21

For a solvent in a solution, the gibbs free energy is ____ than the standard gibbs free energy for a pure solvent at standard pressure. This is because the activity in the equation for gibbs free energy is equal to the __ ___. If there is any solute present, the mole fraction will be ___ than 1 and the gibbs free energy will be smaller. This is the __ ___ behind why pure solvent travels to the solution side. The equilibrium conditions is that the gibbs free energies of both sides are ____.

Answer 21

less, mole fraction, less, driving force, equal

Question 22

the osmotic pressure of the solution with respect to the pure solvent is ___. This pressure results because of the ____ gibbs free energy of the solution in comparison to the solvent. The solvent will migrate through the membrane to increase the ___ ____ on the solution until the free energies are equal

Answer 22

p-p°, smaller, hydrostatic pressure

Question 23

At constant ___ for a ___ solution, the osmotic pressure is proportional to the ___ of the ____

Answer 23

temperature, dilute, molarity/concentration, solute

Question 24

The distribution between ions between two solutions in contact through a semipermeable membrane at equilibrium, with one solution containing an electrolyte protein ion that cannot permeate the membrane

Answer 24

Donnan membrane equilibrium

Question 25

The potential difference across the membrane due to a concentration difference of individual ion on each side of the membrane

Answer 25

donnan potential

Question 26

When there are unequal concentrations of ions across the membrane, there is ____ of the solvent, and thus an ___ ___ difference.

Answer 26

migration, osmotic pressure

Question 27

The inside and outside membrane ___ ___ must both equal ___.

Answer 27

charge balances, 0

Question 28

Any cell delivering current to an external circuit is operating ___ since the current flow is generated by a -___ reaction. This means we can’t measure the full electrical potential of the cell because part of it is being used to generate ___ __. To measure the true cell potential, we must operate under conditions of ___ __ _ _, by using a __ ___ to balance the emf against a known standard voltage so that no current flows.

Answer 28

irreversibly, spontaneous, current flow, 0 current flow, potentiometer circuit

Question 29

By having the spontaneous process occur in an electrochemical cell we can use the decrease in __ __ __ to drive an electron flow through the __ __ and produce net work.

Answer 29

gibbs free energy, external circuit

Question 30

The ____ cell is one where metallic zinc and a copper electrode are immersed in _____ and ___ solutions respectively

Answer 30

daniell, ZnSO4, CuSO4

Question 31

With metal to metal electrodes, the reacting species are in _ ___ with each other and the __ ___. You can use these to figure out when one metal will ___ another from solution

Answer 31

intimate contact, external circuit, displace

Question 32

In a metal to insoluble salt electrode, components must be arranged so they are in ____ amongst themselves and can be in ___ contact with the other half. This is useful in the measurement of ___ ___ ___

Answer 32

contact, electrical, solubility product constants

Question 33

Gas electrodes where two H electrodes have different concentrations of ___ could be used as a ___ ___. The emf would be equal to about ____pH

Answer 33

H+, pH meter, 0.0592

Question 34

The 4 colligative properties are ___ __ ___, __ _ ___, __ __ ___, and __ __

Answer 34

vapor pressure lowering, freezing point depression, boiling point elevation, osmotic pressure

Question 35

Colligative properties assume that the solute is _____ so the only gas present is the solvent vapor, and that the solute is _____ in the solid solvent

Answer 35

non-volatile, insoluble

Question 36

When a solute is added to a pure solvent, the entropy ___, and thus the gibbs free energy _____. The gibbs free energy of the ___ and ___ meanwhile stays the same. This means that the freezing point ____ and the boiling point ____

Answer 36

increases, decreases, solid, liquid, decreases, increases

Question 37

When a substance is added to a pure liquid, there is more ____ in the solution, so there is less tendency for the solvent to ___ and acquire the higher entropy of its ____. in other words, when there is already more entropy in the solution, ____ vapor has to form ___ the free energies of the two phases, so ___ __ is lowered and boiling point is raised

Answer 37

randomness, escape, vapor, less, equalize, vapor pressure

Question 38

Similarly for melting point, the enhanced __ of the solution increases the tendency of the solid to __ and it is able to do so at a ____ temperature than that for a pure solvent.

Answer 38

randomness, melt, lower

Question 39

Colligative properties are related to ___ and not ___ because they change how the molecules move around, not how they interact with each other on an ____ ____

Answer 39

entropy, enthalpy, intermolecular level

Question 40

The largest effects for boiling point elevation will be found for solvents with high ___ __ and low _____ _____ _____

Answer 40

boiling points, enthalpies of vaporization

Question 41

Large freezing point depressions are favoured by solvents with high __ __ and low ___ _ ___

Answer 41

melting points, enthalpies of fusion

Question 42

water has a cryoscopic constant of ____, benzene _____, phenol ___, and camphor ____

Answer 42

1.86, 5.12, 7.27, 40

Question 43

For a given solvent the __ _____ ____ is more accurate in general than __ __ ____ for determining either __ ___ of unknown solutes or the number of particles formed by ___ __ in solution

Answer 43

freezing point depression, boiling point elevation, molecular weights, ionic solutes

Question 44

For ____ such as proteins in solution, because osmotic pressure depends only on the number of ____ molecules, the effects are much ___

Answer 44

macromolecules, solute, smaller

Question 45

During the donnan membrane equilibrium condition, all parts of both solutions must remain ___ ___ at all times so that the ions must diffuse across the membrane together and in ____ ____. Only those species to which the membrane is ____ are able to reach equilibrium across the membrane and only those are included in the donnan conditions

Answer 45

electrically neutral, equal amounts, permeable

Question 46

To measure the donnan potential accurately, we need to add electrodes that are _____ into each solution

Answer 46

ion-selective