Module 5 - Potentiometry

Question 1

What is the field of electro-analytical chemistry in which potential is measured under the condition of no current flow?

Answer 1

Potentiometry

Question 2

What is used to measure potentiometry?

Answer 2

A high impedance voltmeter

Question 3

What methods of analysis are based on measuring the potential of electrochemical cells without drawing appreciable current?

Answer 3

Potentiometric methods

Question 4

What is an instrument used to determine the potential differences between a reference electrode and an indicator electrode?

Answer 4

Potentiometer

Question 5

What can measured potential do?

Answer 5

Can be used to determine the quantity of analyte in terms of concentration

Question 6

Enumerate the components of a potentiometric cell.

Answer 6

Reference electrode | Salt bridge | Analyte | Indicator electrode

Question 7

What is a half-cell with a known potential (Eref); is the left-hand electrode (by convention); easily assembled; and insensitive to analyte concentration?

Answer 7

Reference electrode

Question 8

What is a type of reference electrode that is very common, uses chloride to maintain constant ionic strength, easy to prepare and maintain, is 0.2444 V at 25C, dependent on temperature, and is toxic?

Answer 8

Saturated Calomel Electrode (SCE)

Question 9

What is a reference electrode in potentiometry that uses hydrogen gas but is not often used because of fire hazard and is inconvenient to use and maintain?

Answer 9

Standard hydrogen electorde (SHE)

Question 10

What is the interface between two solutions containing different electrolytes or different concentrations of the same electrolyte?

Answer 10

Liquid junction

Question 11

What occurs at every liquid junction and is caused by unequal mobilities of the + and - ions?

Answer 11

Junction potential

Question 12

What is a type of electrode that Generates a potential (Eind) that depends on analyte concentration, is selective, and gives a rapid and
reproducible response?

Answer 12

Indicator electrode

Question 13

Enumerate the 3 types of indicator electrodes.

Answer 13

I. Metallic
II. Membrane
III. Gas sensing probes

Question 14

What reference electrodes consist of mercury in contact with a solution that is saturated with mercury(I) chloride and that also contains a known concentration of potassium chloride (KCL)?

Answer 14

Calomel reference electrodes

Question 15

What is The most widely marketed reference electrode system consisting of a silver electrode immersed in a solution of potassium chloride that has been saturated with silver chloride?

Answer 15

Silver/Silver-Chloride Reference electrode

Question 16

What electrodes have the advantage that they can be used at temperatures greater than 60°C, while calomel electrodes cannot.

Answer 16

Silver–silver chloride electrodes

Question 17

A type of metallic indicator electrode that uses a pure metal electrode that is in direct equilibrium with its cation in the solution. A single reaction is involved.

Answer 17

electrode of the first kind

Question 18

What type of mettalic indicator also respond to the activities of anions that form sparingly soluble precipitates or stable complexes with such cations and only as indicator electrodes for their own cations?

Answer 18

Electrodes of the second kind

Question 19

What metallic indicator uses relatively inert conductors respond to redox systems?

Answer 19

Inert metallic electrodes for redox systems

Question 20

Glasses that absorb water are said to be _________.

Answer 20

hygroscopic

Question 21

Enumerate the types of membrane indicator electrodes.

Answer 21

1. Glass pH IE
2. Glass IE for other cations
3. Liquid Membrane IE
4. Crystalline-Membrane IE

Question 22

What is is a galvanic cell whose potential is related to the concentration of a gas in a solution?

Answer 22

Gas-sensing probe

Question 23

Which Danish scientist discovered pH measurement?

Answer 23

Soren Sorenson

Question 24

ISFETs stands for __________________.

Answer 24

ion-sensitive field effect transistors