MIDTERM 01 - Complexation Titrations

Question 1

These are a class of reactions that deal with complex formation

Answer 1

Complexation reaction

Question 2

Resulting complex when a ligand contains two or more molecules/groups that can donate electrons

Answer 2

Cheleate

Question 3

Electron donor

Answer 3

Ligand

Question 4

Electron acceptor

Answer 4

Metal ion

Question 5

Most commonly used analytical reagent for complexation reaction

Answer 5

Na2EDTA

Question 6

When a ligand binds to a metal ion through only one atom

Answer 6

Monodentate

Question 7

When a ligand binds to a metal through two atoms

Answer 7

Bidendate

Question 8

When a ligand binds to a metal ion through four atoms

Answer 8

Tetradentate

Question 9

When a ligand binds to a metal ion through six atoms

Answer 9

Hexadentate

Question 10

When a ligand binds to a metal ion through eight atoms

Answer 10

Octadentate

Question 11

When a ligand binds to a metal ion through more than one ligand atom

Answer 11

Multidentate/chelating ligand

Question 12

Ammonia

Answer 12

Monodentate

Question 13

Water

Answer 13

Monodentate

Question 14

Halides

Answer 14

Monodentate

Question 15

Glycine

Answer 15

Bidentate

Question 16

Ethylenediamine

Answer 16

Bidentate

Question 17

Nitriloacetic acid (NTA)

Answer 17

Tetradentate

Question 18

Ethylenediaminetetraacetic acid (EDTA)

Answer 18

Hexadentate

Question 19

Egtazic acid

Answer 19

Hexadentate

Question 20

Diethylenetriaminepentaacetic acid (DTPA)

Answer 20

Octadentate

Question 21

Equilibrium constant for the reaction of a metal with a ligand

Answer 21

Function constant/stability constant

Question 22

Ability of ligands to form more stable metal complexes

Answer 22

Chelate effect

Question 23

Association constant of a chemical reaction

Answer 23

pKn value/Kn

Question 24

Used in EDTA titrations; these are organic compounds which form colored complex ions with metal ion

Answer 24

Metallochromic indicators

Question 25

Type of titration (Standardization of 0.05 M Na2EDTA)

Answer 25

Direct titration

Question 26

Type of titration (Standardization of 0.05 M ZnSO4.7H20)

Answer 26

Direct titration

Question 27

Analyte (Standardization of 0.05 M Na2EDTA)

Answer 27

Chelometric calcium carbonate

Question 28

Analyte (Standardization of 0.05 ZnSO4.7H2O)

Answer 28

Na2EDTA

Question 29

Volumetric solution (Standardization of 0.05 M Na2EDTA)

Answer 29

0.05 M Na2EDTA

Question 30

Volumetric solution (Standardization of 0.05 M ZnSO4.7H2O)

Answer 30

0.05 M ZnSO4.7H2O

Question 31

Buffer (Standardization of 0.05 M Na2EDTA)

Answer 31

NaOH

Question 32

Buffer (Standardization of 0.05 M ZnSO4.7H2O)

Answer 32

Acetic-acid ammonium acetate

Question 33

Indicator (Standardization of 0.05 M Na2EDTA)

Answer 33

Hydroxynaphthol blue

Question 34

Indicator (Standardization of 0.05 M ZnSO4.7H2O)

Answer 34

Dithizone

Question 35

Color transition (Standardization of 0.05 M Na2EDTA)

Answer 35

Red to blue

Question 36

Color transition (Standardization of 0.05 M ZnSO4.7H2O)

Answer 36

Green to rose pink

Question 37

Purpose of using distilled water

Answer 37

Because there is no presence of dissolved ions in distilled water

Question 38

Purpose of drying at 110°C

Answer 38

To remove moisture

Question 39

Purpose of cooling in desiccator

Answer 39

To ensure the right temperature

Question 40

Purpose of diluted hydrochloric acid (HCl)

Answer 40

To dissolve the calcium carbonate (CaCO3)

Question 41

Purpose of using sodium hydroxide TS as a buffer

Answer 41

So that that complex would be stable and any magnesium present as a contaminant would not react

Question 42

Purpose of using acetic acid ammonium acetate as a buffer

Answer 42

Since dithizone gives a transition color at this condition

Question 43

Purpose of using amber bottle in storing ZnSO4 standard solution

Answer 43

Because zinc sulfate is sensitive to heat

Question 44

Is a method in which unwanted purities in the analyte are masked by chemical reagents

Answer 44

Masking

Question 45

Is a compound capable of forming a complexation reaction at a favorable pH condition

Answer 45

Masking agent