Acidimetry And Alkalimetry

Question 1

One of the primary methods used in the determination of content of many pharmacutical substances and excipients

Answer 1

Acid - base titrations

Question 2

Titrations of this nature follow the concept that acid and bases when combined well form it’s correspondings salt and water where at completion will have a shift in PH to which equivalency and endpoints depend on

Answer 2

Acid and base titrations

Question 3

This essentially involves the direct or residual titrimetric analysis of alkaline substances (base) employeing an aliquot of acid and is provided usually in the analytical control of a large number of substances included in the various official compendia

Answer 3

Acidimetery

Question 4

Urea,

Answer 4

Acidimetry: Organic Substances

Question 5

Sodium bicarbonate

Answer 5

Acidimetry: Inorganic substances

Question 6

Sodium Salicylate

Answer 6

Acidimetry: organic substances

Question 7

Milk of magnesia

Answer 7

Acidimetry: Inorganic substances

Question 8

Diphenhydramine

Answer 8

Acidimetry: organic substances

Question 9

Amonium chloride

Answer 9

Acidimetry: Inorganic substances

Question 10

Emetine hydrochloride

Answer 10

Acidimetry: organic substances

Question 11

Calcium Hydroxide

Answer 11

Acidimetry: Inorganic substances

Question 12

Meprobamate

Answer 12

Acidimetry: organic substances

Question 13

Lithium carbonate

Answer 13

Acidimetry: Inorganic substances

Question 14

Paramethadione

Answer 14

Acidimetry: organic substances

Question 15

Zinc oxide

Answer 15

Acidimetry: Inorganic substances

Question 16

Pyrazinamide

Answer 16

Acidimetry: organic substances

Question 17

Conducted by introduction of a standard acid solution gradually into a solution of the base being assayed until chemically equivalent amounts of each have reacted by some change in properties of the mixture

Answer 17

Direct titration method

Question 18

This is used whenever the end point of a direct titration deviates appreciably from the stoichiometric point for the following reasons

Answer 18

Residual or back tritation

Question 19

Basic sample is insoluble in water

Answer 19

Residual (back titration)

Question 20

Rate of reaction with acid is relatively slow

Answer 20

Residual or back titration

Question 21

When the substance under determination fails to give a sharp and distinctly visible end point with an indicator by direct titration

Answer 21

Residual or back titration

Question 22

In usual practice the residual titration is accomplished by allowing to dissolved the substance under estimation in an accurately measured quantity of a standard solution of known strength present in excess and subsequently titrating the excess of the latter with another previously standardized solution

Answer 22

Residual or back titration

Question 23

N1

Answer 23

Normality of acid added with analyte meq / L

Question 24

N2

Answer 24

Normality of base in the buret in meq / L

Question 25

V1

Answer 25

Volume of acid added with analyte in mL

Question 26

V2

Answer 26

Volume of base in the burette in mL

Question 27

Formula for direct titration method

Question 28

Formula for residual or back titration

Question 29

Formula for percentage purity of residual titration

Question 30

Acidic substances are usually determined quantitatively by methods similar to those use for the quantitative determinations of bases

Answer 30

Alkalimetry

Question 31

The quantitative measurement ( direct or residual ) of acidic substances using a basic standard solution

Answer 31

Alkalimetry

Question 32

What are the two methods of Alkalimetry

Answer 32

Direct and residual titration method

Question 33

Directly titrating an exact quantity of the acid, acid salt, acidic substances, with standard alkali solutions

Answer 33

Alkalimetry: Direct titration methods

Question 34

Addition of an excess of the standard alkali solution and subsequently determining the amount in excess by residual titration with standard acid solution

Answer 34

Alkalimetry: Residual titration methods

Question 35

Three principles in alkalimetry

Answer 35

Normality of the solution obtained by dissolving the acidic substance must be approximately the same as that of a titrant The liquid acidic substance to be titrated must be brought to room temperature of (25°C ) before titration because many indicators offer different values at different temperatures The quantity of acid to be taken should be calculated in such a manner that approximately 30 to 40 ml of the previously standardized base shall be utilized for the assay

Question 36

Indicators for inorganic acids

Answer 36

Methyl red and phenolphthaleim

Question 37

Indicators for organic acids

Answer 37

Phenolphthalene, bromothymol blue thymol blue and thymolphthalein

Question 38

This method is mostly applicable to official compounds belonging to the class of esters, acid anhydrides , aldehydes and acid chlorides

Answer 38

Residual titration method

Question 39

In practice this method applies to such substances that normally react to slowly without titrant because of their poor solubility precipitation method so as to convert the substance capable for reaction with the standard base

Answer 39

Residual titration method