Unit 7 – Volumetric Titrimetry

Question 1

These include analytical methods that based on determining the amount of reagent of known strength that required completely with the analyte.

Answer 1

Titrimetric Method

Question 2

What are the types of Titrimetry?

Answer 2

Volumetric T.
Gravimetric T.
Coulometric T.

Question 3

The standard reagent called TITRANT is measured VOLUMETRICALLY.

Answer 3

Volumetric T.

Question 4

The MASS of standard reagent called TITRANT is measured.

Answer 4

Gravimetric T.

Question 5

The quantity of a CONSTANT, DIRECT ELECTRICAL CURRENT of known magnitude is measured.

Answer 5

Coulometric T.

Question 6

The chemical component in the sample that is to be determined.

Answer 6

Analyte

Question 7

Solution that is usually placed in the buret quantitatively reacts with the analyte.

Answer 7

Titrant

Question 8

Solution that is usually placed in the buret quantitatively reacts with the analyte.

Answer 8

Titrant

Question 9

Compound of interest in the sample.

Answer 9

Analyte

Question 10

A reagent of KNOWN CONCENTRATION.

Answer 10

Standard solution

Question 11

It is based on the reaction between the analyte and the titrant.

Answer 11

Titration

Question 12

It is a process of measuring the volume of a solution (of known concentration) that is needed to react completely with the analyte.

Answer 12

Titration

Question 13

T/F
Volume of a solution is the standard solution that will react to the analyte.

Answer 13

T

Question 14

THEORETICAL POINT in titration when the amount of titrant is chemically equivalent to the amount of analyte in the sample.

Answer 14

Equivalence point

Question 15

EXPERIMENTAL ESTIMATION of equivalence point.

Answer 15

Endpoint

Question 16

Point in titration when a physical change occurs at or NEAR the equivalence point.

Answer 16

Endpoint

Question 17

The difference in volume or mass between the equivalence point and end point.

Answer 17

Titration error

Question 18

Substance that undergoes an observable change when endpoint of a titration is reached.

Answer 18

Indicator

Question 19

This will react to excess amount of titrant.

Answer 19

Indicator

Question 20

Successful titrations are based on reactions that are _____, _____.

Answer 20

Stoichiometric, quantitative and fast

Question 21

T/F
Titrant must be STABLE, of known concentration (standard solution) and SELECTIVELY reacts with the analyte.

Answer 21

T

Question 22

T/F
Standard solution is a solution of known concentration.

Answer 22

T

Question 23

T/F
Standard solution should be sufficiently stable.

Answer 23

T

Question 24

T/F
Standard solutions reacts RAPIDLY and COMPLETELY with the analyte.

Answer 24

T

Question 25

T/F Standard solution undergo SELECTIVE REACTION with the analyte.

Answer 25

T

Question 26

T/F The standard solution should react ONLY to the analyte of interest.

Answer 26

T

Question 27

It is the process of determining the exact concentration of the solution.

Answer 27

Standardization

Question 28

T/F In preparation of PRIMARY STANDARD SOLUTION, you should standardize using weighed quantity of primary standard.

Answer 28

T

Question 29

It is HIGHLY PURIFIED compound that serves as reference material for titrimetric analysis.

Answer 29

Primary standard

Question 30

It is made by weighing a pure solid and dissolving it in to make a solution.

Answer 30

Primary standard

Question 31

What are the requirements for primary standard?

Answer 31

- High purity – preferably 99.9% or better - Atmospheric stability - Absence of hydrate water - Available at modest cost - Soluble in titration medium - Has large molar mass to minimize relative error associated with weighing

Question 32

Give at least one example of PRIMARY STANDARD SOLUTION.

Answer 32

Potassium Acid Phthalate (KHP) Benzoic Acid Arsenious Oxide Sodium Oxalate

Question 33

A solution that is standardized against another standard solution.

Answer 33

Secondary standard solution

Question 34

A solution in which the concentration of dissolved solute has solute has not been determined from the weight of the compound dissolved but by reaction (titration) of a volume of the solution against a measured volume of a primary standard solution.

Answer 34

Secondary standard solution

Question 35

Give at least one example of SECONDARY STANDARD SOLUTION.

Answer 35

NaOH HCl KMnO4

Question 36

T/F Endpoints of titrations must occur at or near equivalence point.

Answer 36

T

Question 37

What are the typical indicator change in titration?

Answer 37

- Appearance or disappearance of a COLOR - Change in color - Appearance or disappearance of TURBIDITY

Question 38

Which of the following is/are based on the reaction involved between ANALYTE and TITRANT? A. Acid-base or neutralization titration B. Precipitation titration C. Complexation titration D. Oxidation-reduction titration E. All of the above

Answer 38

E

Question 39

Which of the following is/are based on how the amount of analyte is determined? A. Direct titration method B. Replacement or Indirect titration method C. Back-titration D. All of the above

Answer 39

D

Question 40

A method wherein the titrant DIRECTLY reacts with the analyte.

Answer 40

Direct titration method

Question 41

T/F Reaction ratio depends on the balanced chemical reaction.

Answer 41

T

Question 42

T/F The amount of analyte/titrant is expressed in units of moles or millimoles.

Answer 42

T

Question 43

The analyte is CONVERTED to ANOTHER substance by a preliminary reaction.

Answer 43

Replacement or Indirect titration method

Question 44

In replacement or indirect titration method, the new substance (X) is _____ proportional to the amount of _____. This new substance is then determined by _____. A. directly; analyte; titration B. inversely; analyte; titration C. directly; titrant; analyte D. inversely; titrant; analyte

Answer 44

A

Question 45

The analyte is made to react with a known amount of excess standard solution (titrant1). The excess reagent is titrated with a second standard solution (titrant2).

Answer 45

Back-titration method