Ch 20 Applications of Oxidation/Reduction Titrations

Question 1

The analyte in an oxidation/reduction titration must be in a single oxidation state at the outset. Often, however, the steps that precede the titration, such as dissolving the sample and separating interferences, convert the analyte to a mixture of oxidation states. Therefore, we need

Answer 1

Auxiliary Oxidizing
and Reducing Reagents

Question 2

The analyte solution must be
filtered to remove granular or powdered forms of the metal. An alternative to filtration
is the use of a

Answer 2

reductor

Question 3

reductor that has a diameter of about 2 cm and holds a 40- to 50-cm column of amalgamated zinc

Answer 3

Jones reductor

Question 4

reductor where a granular metallic silver held in a narrow glass column is the reductant, sometimes carried out from hydrochloric acid solutions of the analyte

Answer 4

walden reductor

Question 5

What are some Auxiliary Oxidizing Reagents

Answer 5

Sodium Bismuthate
Ammonium Peroxydisulfate
Sodium Peroxide and Hydrogen Peroxide

Question 6

is a sparingly soluble solid and a powerful oxidizing agent capable, for example, of converting manganese(II) quantitatively to permanganate ion.

Answer 6

Sodium bismuthate (NaBiO3)

Question 7

is also a powerful oxidizing agent that uses traces of silver ion as catalyst. In acidic solution, it converts chromium(III) to dichromate, cerium(III) to cerium(IV),
and manganese(II) to permanganate.

Answer 7

Ammonium peroxydisulfate, [(NH4)2S2O8]

Question 8

is a convenient oxidizing agent either as the solid sodium salt or as a dilute solution of the acid

Answer 8

Sodium Peroxide and Hydrogen Peroxide

Question 9

direct titration of oxidizing analytes using reductants namely;

Answer 9

Iron(II) Solutions
Sodium Thiosulfate

Question 10

is a moderately strong reducing agent that has been widely
used to determine oxidizing agents by an indirect procedure in which iodine is an
intermediate

Answer 10

Thiosulfate ion (S2O3^-2)

Question 11

Common Oxidants Used as Standard Solutions

Answer 11

Potassium permanganate
Potassium bromate
Cerium (IV)
Potassium dichromate
Iodine

Question 12

Strong Oxidants Used as Standard Solutions

Answer 12

Potassium Permanganate and Cerium(IV)

Question 12

Potassium Permanganate vs. Cerium(IV) - more advantageous?

Answer 12

Cerium(IV)

Question 13

Potassium Permanganate vs. Cerium(IV) - often used?

Answer 13

Potassium Permanganate - due to its intense color that serve as an indicator in titrations

Question 14

widely used primary standard in Standardizing Permanganate and Ce(IV) Solutions

Answer 14

Sodium oxalate

Question 15

is a type of catalysis
in which the product of a reaction
catalyses the reaction. This phenomenon causes the rate of the reaction to
increase as the reaction proceeds.

Answer 15

Autocatalysis

Question 16

An oxidant that is indefinitely stable, can be boiled without decomposition, and does not react with hydrochloric acid. It has a lower electrode potential than Potassium Permanganate and Cerium(IV).

Answer 16

Potassium dichromate

Question 17

is a weak oxidizing agent used primarily for the determination of strong reductants. Though it has a smaller electrode potential, it imparts a degree of selectivity that makes possible the determination of strong
reducing agents in the presence of weak ones.

Answer 17

Iodine solution

Question 18

An oxidant that is a source of Bromine

Answer 18

Potassium Bromate

Question 19

An oxidant that is used to determination 8-hydroxyquinoline and estimate the olefinic unsaturation in fats, oils, and petroleum products.

Answer 19

bromine

Question 20

is based on the oxidation of sulfur dioxide by iodine. In a
solvent that is neither acidic nor basic—an aprotic solvent

Answer 20

Karl Fischer reaction

Question 21

An end point in a Karl Fischer titration can be observed visually based on the _________ of the excess reagent

Answer 21

brown
color

Question 22

Is based on the oxidation of sulfur dioxide by iodine

Answer 22

Karl fischer reaction

Question 23

Detecting the endpoint of the carl fisher titration can be observed visually based on

Answer 23

Brown color of the excess reagent

Question 24

The orange color of a dichromate solution is not intense enough for use in end point detection. What is the indicator for the titration with this reagent?

Answer 24

Diphenylamine sulfonic acid

Question 25

An excellent primary standard for thiosulfate solutions

Answer 25

Potassium iodate

Question 26

In standardizing iodine solutions, what is the reagent used as the primary standard?

Answer 26

Anhydrous sodium thiosulfate