Electroanalytical Methods

Question 1

In most electro analytical methods, it’s either a measure of _____ or _____

Answer 1

Current, potential

Question 2

Measured in an electrochemical cell at a fixed potential

Answer 2

Current

Question 3

Measured while the current is fixed at some constant values or zero

Answer 3

Potential

Question 4

Electro analytical can be ____ and ____

Answer 4

Interfacial and bulk methods

Question 5

Interfacing methods are of two types. ____ use potentiometric measurements while _____ measure other variables while the cell pitential is controlled

Answer 5

Static, dynamic

Question 6

Potential of an electrochemical cell is measured under ____ conditions in a potentiometric analysis

Answer 6

Static

Question 7

An electrode whose potential remains constant and against which other potentials can be measured

Answer 7

Reference electrode (anode)

Question 8

Electrode whose potential is a function of the Concentra of analyte

Answer 8

Indicator electrode (cathode)

Question 9

Reference electrode that consists of a Pt wire nthat is connected to a Pt surface in contact with an aqueous solution containing 1M H+ in equilibrium with H2 gas at a pressure of 1 atm

Answer 9

Standard Hydrogen Electrode (SHE)

Question 10

Reference electrode that consists small amount of Hg mixed with some solid HgCl2, solid KCl, and enough saturated KCl solution to moisten the mixture

Answer 10

Saturated Calomel electrode

Question 11

Reference electrode that functions as redox electrode and the equilibrium is between Ag and AgCl

Answer 11

Ag/AgCl electrode

Question 12

Metallic and ion-selective electrodes (membrane electrodes) are types of _____

Answer 12

Indicator electrodes

Question 13

Types of metallic electrode where in metals including Ag, Cu, Hg, Pb, Zn can serve as an indication for their own

Answer 13

Electrode of the first kind

Question 14

Types of metallic electrode where in metal in contact with slightly soluble precipitate involving the metal cation; the electrode responds to anion concentration

Answer 14

Electrode of the second kind

Question 15

Types of metallic electrode where in an inert electrode (Pt and Au) that serves as a source or sink for electrons for a redox half- reaction

Answer 15

Redox electrode

Question 16

Electrode made of doped glass membrane sensitive to soecific ion. Used in pH meters.

Answer 16

Glass ion-selective electrode

Question 17

An ion-selective electrode based on sparingly soluble inorganic crystalline material

Answer 17

Solid-state ion-selective electrode

Question 18

An ion-selective electrode in which chelating agent is incorporated into a hydrophobic membrane

Answer 18

Liquid-based ion-selective electrode

Question 19

An ion-selective electrode in which chelating agent is incorporated into a hydrophobic membrane

Answer 19

Liquid-based ion-selective electrode

Question 20

An ion-selective electrode that responds to the concentration of a dissolved gas

Answer 20

Gas-sensing electrode

Question 21

Measure of the response of an ion-selective electrode to other ions

Answer 21

Selectivity coefficient

Question 22

Consist of a tube within a tube, the inner one housing the pH indicator electrode and the outer one housing the reference electrode and it’s salt bridge

Answer 22

Combination pH-reference electrode

Question 23

Common reference electrode used in combination pH electrodes

Answer 23

Ag/AgCl electrode

Question 24

In a cell, when the current is present, two additional phenomena must be considered which is ____ and ____

Answer 24

IR drop, polarization

Question 25

An electrode phenomenon that may affect either or both of the electrodes in a cell.

Answer 25

Polarization

Question 26

Polarization phenomena can be divided into two categories. Which one occurs because of the finite rate of mass transfer from the solution to the electrode surface

Answer 26

Concentra polarization

Question 27

Movement of material from one location to another in three mechanisms: convection, migration, diffusion

Answer 27

Mass transfer

Question 28

Results from mechanical motion of the solution as a result of stirring, vibration, or temperature differences

Answer 28

Convection

Question 29

Movement resulting from stirring, vibration, or temperature differences

Answer 29

Convection

Question 30

Movement of ions brought about by electrostatic attraction between the ions and the electrode of the opposite charge

Answer 30

Migration

Question 31

Motion of species caused by a concentration gradient

Answer 31

Diffusion

Question 32

The higher the current the largegr the concentration gradient until the surface concentration falls to zero wherein the max possible current called ___ is obtained.

Answer 32

Limiting current

Question 33

Electro analytical method that involve measuring the quantity of electricity needed to convert the analyte quantitatively to a different oxidation state

Answer 33

Coulometry

Question 34

The end point is determined _____ in volumetric procedure, whereas in the coulometric method, the end point is determined _____.

Answer 34

Potentiometrically, electrochemically

Question 35

Uses volumetric or coulometric titration to determine trace amounts of water in a sample

Answer 35

Karl Fischer Titration

Question 36

Group of methods in which information about the analyte is obtained by measuring current as a function of applied potential under conditions where concentration polarization exists

Answer 36

Voltammetry

Question 37

Resulting plot of currenta against applied potential

Answer 37

Voltammogram

Question 38

Electrode whuch the analyte is oxidized or reduced is called ____

Answer 38

Working electrode

Question 39

Current plateau at top of voltammetric wave is called ____

Answer 39

Limiting current

Question 40

Form of voltammetry that uses dropping mercury electrode

Answer 40

Polarography

Question 41

Most efficient profile for voltammetry that applies a square wave superimposed on a staircase voltage ramp

Answer 41

Square Wave Polarography

Question 42

Form of voltammetry in which the solution is mechanically stirred

Answer 42

Hydrodynamic voltammetry

Question 43

Form of voltammetry in which a fixed potential range is employed where the voltage is scanned from a lower limit to an upper limit

Answer 43

Linear Sweep Voltammetry (LSV)

Question 44

Form of Voltammetry where the voltage is swept between two values at a fixed rate. But when the voltage reaches the higehr limit, the scan is reversed and the voltage is swept back to the lower limit

Answer 44

Cyclic voltammetry

Question 45

Form of voltammetry in which the analyte is first deposited on the electrode and the stripped

Answer 45

Stripped voltammetry (anodic, cathodic, and adsorptive)