Electrochemistry (12)

Question 1

cathode and anode

Answer 1

AN OX and RED CAT

Anode is the site of oxidation. it attracts anion

Cathode is the site of reduction. it attracts cation

Question 2

electromotive force (emf)

Answer 2

if the emf is positive, the cell is able to release energy, ΔG < 0

if the emf is negative, the cell must absorb energy, Δ
ΔG > 0

Question 3

electron flow vs. current flow

Answer 3

electron flow: anode —> cathode (A –> C alphabet order)

current flow: cathode –> anode

Question 4

Cell diagram

Answer 4

Zn | Zn2+ (1M) || Cu 2+ (1M) | Cu

reactants and products are always listed from left to right in this form:
anode | anode solution || cathode solution | cathode

single verticle line means phase boundary
double verticle line means salt bridge or some other type of barrier

Question 5

Galvanic (voltaic) cells

Answer 5

house spontaneous rxn ΔG < 0 with a positive electromotive force Ecell > 0

generate electrical energy

Question 6

Electrolytic cells

Answer 6

houses nonspontaneous rxn ΔG > 0 with a negative electromotive force Ecell > 0. These nonspontaneous cells can be used to create useful products through electrolysis

require the input of energy to proceed

Question 7

Rechargeable batteries

Answer 7

Can experience charging (electrolytic) and discharging

(galvanic) states.

Question 8

Lead-Acid

Answer 8

Discharging: Pb anode, PbO2 cathode in a concentrated

sulfuric acid solution. Low energy density.

Question 9

Standard reduction potentials E°red

Answer 9

calculated by comparison to the standard hydrogen electrode (SHE) under the standard conditions of 298K, 1atm, and 1M.

The positive