Electrochemistry

Question 1

Contained systems in which redox rxns occur are known as ?

Answer 1

Electrochemical cells

Question 2

For all electrochemical cells, the electrode where oxidation occurs is called the_____, & the electrode where reduction occurs is called the ______.

Answer 2

anode & cathode (respectively)

Question 3

The voltage or electrical potential difference of the cell is known as ?

Answer 3

Electromotive force (emf)
+: cell able to release energy (spontaneous)
-: cell must absorb energy (nonspontaneous)

Question 4

Galvanic (voltaic) cells are commonly used as ?

Answer 4

Batteries 🔋

-Rxns in cells spontaneous

Question 5

What is the main purpose of the salt bridge ?

Answer 5

To exchange anions & cations to balance or dissipate newly generated charges

Question 6

What is the direction of electron flow in galvanic cells ?

Answer 6

From anode to cathode

Question 7

Electrolytic cells differ from galvanic cells in what way ?

Answer 7

They house non-spontaneous rxns & require energy input

*Driven by electrolysis: chemical compounds decomposed

Question 8

Concentration cells are special types of galvanic cells. What distinguishes them as special ?

Answer 8

Electrodes are chemically identical

Question 9

A cell that can function as both a galvanic & electrolytic cell is known as ?

Answer 9

Rechargeable cells/battery

• Lead acid battery
• Nickel-cadmium batteries

Question 10

The measure of a battery’s ability to produce power as a function of its weight is known as ?

Answer 10

Energy density

Question 11

How do galvanic & electrolytic cells differ in electrode charge designations ?

Answer 11

GC: anode (negative, low electrical potential) travels to cathode (positive, high electrical potential); current flows oppositely
EC: anode (positive), cathode (negative)

Question 12

Which technique is used to separate amino acids or polypeptides based on their isoelectric points (pI)?

Answer 12

Isoelectric focusing

Question 13

The tendency of a species to gain electrons & to be reduced is defined as ?

Answer 13

Reduction potential

Question 14

Standard reduction potentials are measured under what standard conditions ?

Answer 14

1 atm pressure
1 M conc.
25oC (298K)
*more +:greater tendency for reduction
*less +: greater tendency for oxidation

Question 15

What kind of voltmeter draws no current & gives a more accurate reading of the difference in potential between 2 electrodes ?

Answer 15

Potentiometer