Electrochemistry Flashcards Preview

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Flashcards in Electrochemistry Deck (33):
1

oxidation

loss of electrons

2

reduction

gain of electrons

3

what agent is the oxidized atom

reducing agent

4

what agent is the reduced atom

oxidizing agent

5

what happens at anode

oxidation

6

what happens at cathode

reduction

7

galvanic cell function

flow of electrons create an electric current that can do work in a redox reaction. spontaneous redox reactions generate electric currents

8

anode

electron source

9

cathode

electron sink

10

how do electrons flow in galvanic cell

anode to cathode

11

salt bridge anion and cation destinations

anion goes to anode, cation goes to cathode

12

what do salt bridges complete

circuit

13

what are the standard conditions

25 degrees celcius, 1 atm, 1 M

14

what is free energy change for a redox reaction?

delta G = -nFE

15

What must cell voltage and free energy be to be spontaneous

cell voltage positive, free energy negative

16

If a reduction potential is negative, what are characteristics of reactant

better as a reducing agent, weak oxidizing agent

17

if a reduction potential is positive, what are characteristics of reactant

stronger as an oxidizing agent and weaker as a reducing agent

18

What are nonstandard conditions

when solution does not equal 1 M and nernst equation must be used

19

concentration cell

galvanic cell with identical electrodes but has half cells with different ion concentrations

20

what is anode in concentration cell

lower concentration solution

21

what is cathode in concentration cell

higher concentration solution

22

when does reaction stop in concentration cell

when concentrations are equal

23

what is standard cell voltage in concentration cell

zero, since ions in two beakers have same identities

24

redox indicator

uses change in color to determine endpoint. change is due to change in oxidation state

25

what makes a redox indicator an ideal indicator

having a high redox potential for determination of solution with oxidizable species

26

At half equivalence point

oxidized and non oxidized are equal and Q = 1. E= E prime

27

Electrolytic Cells

Use external voltage (battery) to create electric current that forces nonspontaneous reactions to occur.

28

Electrolysis

use of electrolytic cells

29

Electroplating

electrolytic cells are used for plating thin layer of metal on top of another material

30

Anode in electrolytic cells charge

positive, because electrons are forced to move

31

Cathode in electrolytic cells charge

negative, because electrons are forced to move

32

Faraday's Law of electrolysis

amount of chemical charge is proportional to amount of electricity that flows through cell

33

Faraday

magnitude of charge on 1 mole of electrons