NON-AQUEOUS AND DOUBLE INDICATOR

Question 1

refers to a type of titration in which the analyte
substance is dissolved in a solvent which does
not contain water.

Answer 1

Non – Aqueous
Titration

Question 2

Non – Aqueous
Titration most common titrimetric procedure used in

Answer 2

pharmacopoeial assays

Question 3

When to use
Non –
Aqueous
Titration?

If reactants are insoluble in
water such as ______

Answer 3

organic acids
and bases

Question 4

When to use
Non –
Aqueous
Titration?

If reactants
are ______
with water

Answer 4

reactive

Question 5

When to use
Non –
Aqueous
Titration?

______ must be
avoided or at least
limited to ______

Answer 5

Moisture

0.05%

Question 6

Advantages OF NON-AQUEOUS TITRATION

Answer 6

1. Titration of water insoluble drugs
2. Titration of weakly acidic and basic
   drugs
3. Titration of water sensitive drugs like
   ASA and polyphenols
4. Wider pH range as compared to
   water
5. Simple, fast, precise and accurate

Question 7

Bronsted-Lowry
❖ Acid is a

Answer 7

PROTON DONOR

Question 8

Bronsted-Lowry Base is a

Answer 8

PROTON ACCEPTOR

Question 9

solvent with neutral charge and are chemically inert

Answer 9

APROTIC SOLVENTS

Question 10

solvents that generally have low dielectric constant

Answer 10

APROTIC SOLVENTS

Question 11

EXAMPLES OF APROTIC SOLVENTS

Answer 11

CHLOROFORM AND BENZENE

Question 12

solvents which are basic character and tend to react with the acids they come in contact with, leading to the formation of solvated protons

Answer 12

PROTOPHILIC SOLVENTS

Question 13

EXAMPLES OF PROTOPHILIC SOLVENTS

Answer 13

AMMONIA AND PYRIDINE

Question 14

more acidic in character and tends to have levelling effect on the bases they come in contact with.

Answer 14

PROTOGENIC SOLVENTS

Question 15

EXAMPLES OF PROTOGENIC SOLVENTS

Answer 15

SULPHURIC ACID AND ACETIC ACID

Question 16

protophilic as well as protogenic

Answer 16

AMPHIPROTIC SOLVENTS

Question 17

Examples of amphiprotic solvents

Answer 17

Acetic acid and alcohol

Question 18

Disadvantages of non-oqueous titration

Answer 18

Temperature, moisture and carbon dioxide should be controlled properly
Expensive solvents
Volatile solvents
Some are hazardous

Question 19

Acid titrant for non-aqueous titration

Answer 19

Perchloric acid in glacial acetic acid or dioxane

Question 20

Base titrant for non-aqueous titration

Answer 20

Sodium metoxide, lithium metoxide in ethylenediamine, n-butylamine and morpholine

Question 21

Acidimetric weak bases

Answer 21

❖Crystal violet, malachite green,
quinaldine red, methylrosaniline

Question 22

Acidimetric relatively stronger bases

Answer 22

Methyl orange, methyl red, Thymol blue

Question 23

Alkalimetric weak acid

Answer 23

Azoviolet

Question 24

Alkalimetric strong acid

Answer 24

Thymol blue

Question 25

It is used to determine the composition of certain mixtures

Answer 25

Double indicator titration

Question 26

Phenolphthalein changes in color within the pH range of

Answer 26

8.0-10

Question 27

Methyl orange changes in color within the pH range of

Answer 27

3.2 to 4.4

Question 28

If phenolphthalein is higher than methyl orange that is used in the hydrochloric acid what could be the possible composition of the mixture

Answer 28

Sodium hydroxide, sodium carbonate

Question 29

If phenolphthalein is lower than methyl orange that is used in the hydrochloric acid what could be the possible composition of the mixture

Answer 29

Sodium carbonate, sodium bicarbonate