Redox and Electrochemical

Question 1

What is characteristic of indicator in redox titration?

Answer 1

it is right between ox to red form > light tinge, not at endpoint

Question 2

What is equiv point in redox tirtration:

Answer 2

equiv pt # of molwes

- amount of electrons given up and absorbed

Question 3

What will benedict’s reagant mixed with, with heat, and change color?

Answer 3

glucose due to aldehyde

Question 4

How do you calculate normality in redox titraiton?

Answer 4

change in oxidation state of species multipled by molarity

Question 5

What is the symbol and units for reduction potential?

Answer 5

E knot

• usually in volts which is measure of electrial potential
• refers to reduction half reaction

Question 6

If you have two half reactions, each with positive reduction potential, how do you decide which one is reversed?

Answer 6

more positive remains, as this is more spontaneous in reduction side
- less positive is reversed and sign inverted

Question 7

If you have two elements of oxidation potentials, how do you determine which is a better oxidizing agent?

Answer 7

• most likely to get reduced

- so the less positive oxidizing potential which corresponds to the more positive reduction potential9

Question 8

How can a non-spont reaction be pushed to proceed?

Answer 8

Infusion of energy

Question 9

Electrochemical cell basic definition

what is the site of Reduction and Oxiddtion?

Answer 9

• house redox reaction, generate or use energy
• Anode: oxidation
• Cathode: reduction

Question 10

what are the two types of eletrochemical cells?

Answer 10

Galvanic (voltaic) and electrolytic

Question 11

Galvanic

Answer 11

• spont redox > generate pos potential difference to drive current
• E not cell always positive

Question 12

How can you find reaction direction?

Answer 12

• identify cathode reaction: more positive reduction potential
• flip the oxidation side and add together
• gone wrong if you get negative value

Question 13

Daniel Cell

Answer 13

• electrodes connected by copper wire: electrons from anode to cathode
• ions not participating travel to other > equalize electronic flow
• anode|anode solution left || cathode solution | cathode right
• anode neg, cathode pos
• two half reaction sphysically sep

Question 14

Concentration cell

Answer 14

• two half-reactions are in the same cell

- same material, different concentrations > one is more negative until equalize

Question 15

Electrolytic cell basic setup and biochemical applications:

Answer 15

• require energy input to drive nonspont reaction
• always neg Enot cell
• breakdown compounds
• anode positive, cathode negative
• Isoletric focusing and SDS-PAGE

Question 16

What is electroplating?

Answer 16

nonspont reduction of metal ion ins solution >

mol(metal) = It / nF

Question 17

Rechargeable battery recharges and discharges: which parts correspond to galvanic and electrolytic cells

Answer 17

galvanic: discharging, because produces energy
electrolytic: recharging, bc require energy input

Question 18

Nersnt Equation actual cell potential breakdown

Answer 18

E’ = Enot - RT/zF ln Q

E’: actual cell potnetial
z: mol transferred
F: Faraday constant = 100K C/mol

Question 19

Nernst Phys condition

Answer 19

E’ = Enot cell - 0.06/z logQ

Question 20

what are two gibbs free enregy equations

Answer 20

delta G’ = -nFEnot cell = -RTlnKeq

Keq correlates to Enot cell c

Question 21

what are the components of delta G, Keq, Ecell not of spont and nonspont reaction:

Answer 21

spont:
- delta G negative, Keq >1, Enot cell pos

nonspont
- delta G pos, Keg<1, E not cell neg