Quiz 2

Question 1

Ox / Redox pneumonic

Answer 1

Oil Rig
Oxidation is loss
Reduction is gain

Question 2

Oxidizing agent

Answer 2

gains electrons from an ox/redox reaction. The oxidizing agent is reduced

Question 3

Reduction agent

Answer 3

provides e- for a redox reaction. The reducing agent is oxidized

Question 4

Primary cells

Answer 4

Non-reversible
Non-rechargeable
Considered a “dry” cell
comes from reactions that are generally not reversible

Question 5

Secondary Cell

Answer 5

Reversible and Rechargeable because reactants remain on electrode surface
Reversal of e- flow lets reactants be regenerated by reverse reaction
“Wet” cell
recyclable like a Li-on battery

Question 6

Spontaneous vs non-spontaneous

Answer 6

Spontaneous (such as a galvanic cell) has a negative delta G for the reaction.
Non-spontaneous are driven by application of current. Positive delta G (occurs in electrolytic cell)

Question 7

Balancing redox reactions

Answer 7

• write the equation
• What is oxidized, what is reduced? write the half reactions
• balance the halves, use water to balance O, H+ to balance hydrogen
• balance with electrons to correct for charge
• add the half reactions

Question 8

Galvanic cell diagram

Answer 8

anode (left) is oxidized providing electron flow right to the cathode. potassium sulfate salt bridge connects the jars under the circuit with electron flow

Question 9

why is the salt bridge needed

Answer 9

salt bridge allows for flow of ions from cathode to anode

Question 10

standard conditions

Answer 10

1.0m concentration
1 bar, 1.01 atm pressure
standard states
298K

Question 11

When determining standard reduction potentials…

Answer 11

remember that you may need to flip a charge for the reverse reaction

Question 12

Latimer Diagrams

Answer 12

most oxidized species is on the left

Question 13

Disproportionation

Answer 13

element is simultaneously oxidized and reduced

Question 14

Comproportionation

Answer 14

element at two oxidation states is reduced to one

Question 15

Frost diagram

Answer 15

the most stable oxidation state is the lowest point on the diagram

Question 16

What species will disproportionate on a frost diagram?

Answer 16

those on a convex curve (top of curve less stable)

Question 17

what species will comproportionate on a frost diagram?

Answer 17

those on a concave curve (bottom [cave in] more stable, two will try to take this form)

Question 18

What is the strongest oxidizer in a frost diagram?

Answer 18

top left position

Question 19

what is the strongest reducing agent in a frost diagram?

Answer 19

top right position

Question 20

Battery set up

Answer 20

Left jar: anode (oxidation) an ox!
Fe --> Fe2+ +2e-
Right jar: cathode (reduction) red cat!
Cu2+ +2e- --> Cu
Electron flow: anode to cathode, left to right
Ion flow: 

Size in the anode starts to deteriorate, size in cathode has sick gains

Question 21

Cell notation

Answer 21

Anode solid | Anode aqueous || Cathode aqueous | Cathode Solid

Question 22

Ecell =

Answer 22

E cathode - E anode

Question 23

In equation form, what is different between the anode and the cathode

Answer 23

the anode has the e- on the right (oxidation)

the cathode has the e- on the left (reduction)

Question 24

3 cell types

Answer 24

simple cubic: spheres touching on axis (bad orange stack, space unfilled)
Face centered cubic: bad orange stack with support (space filled)
Body centered cubic: best orange stack (all spheres lined up on radius)

Question 25

Solids organization tree

Answer 25

Pure solids

• Amorphous
• Crystalline
• – covalent
• – Ionic
• – Molecular

Question 26

ABA, CBA

Answer 26

hexagonal closest packing
- hex, tri, hex
cubic closest packing
hex, tri, tri, hex

Question 27

Holes

Answer 27

Octahedral
- three spheres offset by three opposite oriented spheres lives a hex
Tetrahedral
- three spheres leaves a triangle
Cubic
- space left by bad orange packing

Question 28

polymorphism

Answer 28

the ability of a solid to have multiple configurations in the solid state (chocolate and bloom, carbon allotrope)

Question 29

Ketelaar triangle

Answer 29

used to show composition of alloys

may occasionally result in Zintl phase in which two alloys are unaligned: very brittle

Question 30

Alloy types

Answer 30

pure
substitutional: a similar sized sub for parts of metal
interstitial: fill out open space with smaller metal
hybrid

Question 31

Born - Haber Cycle

Answer 31

Energy for sublimation = +
Ionization Energy 1 = +
Dissociation energy(separate a diatomic, only need 1 so half) = +

Electron Affinity energy = -
Lattice Energy from bond formation = large -

net result negative = favored reaction

Question 32

Which is larger: anion or cation

Answer 32

Anions tend to be larger

Question 33

Which is negatively charged: anion or cation

Answer 33

anion

Question 34

frost diagram axis

Answer 34

y axis is delta G
x axis is oxidation number
slope = Ecell

Question 35

N type vs P type

Answer 35

N type is donor band. Elements from group five can donate an extra electron to reduce band gap
P type is an acceptor band and can receive electrons density to bridge the band gap (III)

both are doped(extrinsic) semi-conductors

Question 36

band gap types

Answer 36

metal: partial overlap
semi-metal: direct contact between full and empty band
insulator: large gap

Question 37

silicate structures

Answer 37

isolated tetrahedral
single chains
double chains
sheet
framework

Question 38

zeolite composition

Answer 38

Si, Al, O

Question 39

Organosilicones

Answer 39

chemically inert
heat stable
water repellant

Question 40

metal characteristics

Answer 40

outer electrons are able to wander through
electric fields move them through
free electrons make for good transfer of energy