FIXED OILS AND FATTY SUBSTANCES

Question 1

value or number of physical and chemical
property. Correctness of these values determines the
quality of substances judged

Answer 1

CONSTANT

Question 2

CONSTANTS INCLUDE:

Answer 2

❖ specific gravity
❖ melting point
❖ congealing point
❖ refractive index
❖ optical activity
❖ acid value, saponification value, ester value, iodine value,
acetyl value, hydroxyl value, unsaponifiable matter,
water and sediment

Question 3

The purity of fixed oils, fats, waxes, resins, etc. can not be
ascertained by the usual methods based on

Answer 3

gravimetric
or volumetric processes

Question 4

The determination of these constants are made in conjunction
with the study of ______
tests for the substance analyzed and for the presence of
adulterants serve as a basis of the purity and quality of such
substances

Answer 4

color, odor, taste and special identity

Question 5

compounds consisting of fatty acids combined with
glycerol via ester linkages

Answer 5

FATS

Question 6

Fats – compounds consisting of

Answer 6

fatty acids combined with
glycerol via ester linkages

Question 7

an ESTER derived from
glycerol and three fatty acids

Answer 7

TRIGLYCERIDES

Question 8

are mixture of glyceryl esters
of high molecular weight fatty acids like palmitic (16),
stearic (18) and oleic( 18) acids.

Answer 8

Fixed oils and fats

Question 9

Contain relatively high quantities of liquid
glycerides (glyceryl oleate)

Answer 9

FIXED OILS

Question 10

Fixed oils contain relatively high quantities of

Answer 10

liquid
glycerides (glyceryl oleate)

Question 11

contain large amounts of solid glycerides (glyceryl
stearate).

Answer 11

FATS

Question 12

Fats contain large amounts of

Answer 12

solid glycerides (glyceryl
stearate)

Question 13

HAVE DOUBLE BONDS

Answer 13

OILS

Question 14

are esters of high molecular weight
monohydric alcohols and high molecular weight fatty acids.

Answer 14

WAXES

Question 15

Waxes are

Answer 15

esters of high molecular weight
monohydric alcohols and high molecular weight fatty acids.

Question 16

Sources include both plants (soybean, carnauba) and animals
(spermaceti, Ambergris

Answer 16

WAXES

Question 17

are natural or induced solid or semi-solid
exudates from plants characterized by being insoluble in
water, soluble in alcohol and ether, crystallizable and softening or
melting at a moderate heat.

Answer 17

RESINS

Question 18

are substances containing benzoic or cinnamic
acids or esters of these

Answer 18

BALSAMS

Question 19

The fats and oils to be employed in the
determination of their chemical constants
should undergo preliminary treatment if they
are ______ due to separation of stearin.

Answer 19

turbid

Question 20

oils should be made clear by ______
their container on a water bath at 50°C until
the turbidity disappears

Answer 20

heating

Question 21

ACID value -also called

Answer 21

Acid Number or Acidity
Index

Question 22

Defined as the number of milligrams of potassium
hydroxide required to neutralize the free acids in one
gram of oil, fat, wax, resin, balsam or other similar
substances of complex composition.

Answer 22

ACID VALUE

Question 23

It may be expressed as the number of milliliters of
0.1-N sodium hydroxide required to neutralize the free
acids in 10 grams of sample

Answer 23

ACID VALUE

Question 24

are due to hydrolysis of the esters that
compose them

Answer 24

FREE ACIDS

Question 25

The hydrolysis is caused by

Answer 25

BACTERIAL OR CATALYTIC ACTION

Question 26

If a substance has a high acid value, it does not indicate _____ but _____ during their preparation, purification or storage.

Answer 26

rancidity hydrolytic decomposition

Question 27

Saponification Value ❖ Also known as the

Answer 27

Saponification Number or Koettsdorfer Number

Question 28

Defined as the number of mg of potassium hydroxide required to neutralize the free acids and saponify the esters in 1 gram of fat, fatty oil, wax, resin, balsam or other substances of similar composition.

Answer 28

SAPONIFICATION VALUE

Question 29

Determination of this constant helps in the detection of the presence of glycerides of fatty acids which contain less than 16 or more than 18 carbon atoms

Answer 29

SAPONIFICATION VALUE

Question 30

saponification value is ______proportional to the average of the molecular weights of the fatty acids found in the sample

Answer 30

inversely

Question 31

High SV, samples contain ______

Answer 31

low MW fatty acids

Question 32

HCl cannot be substituted with ____because K2 SO4 which would be the product of the neutralization will not dissolve in the alcoholic solution and interfere with the observation of the endpoint

Answer 32

H2 SO4

Question 33

______ is more advantageous than the aqueous solution because the alcohol acts as a solvent for the oil and the products of saponification which are insoluble in water.

Answer 33

Alcoholic KOH

Question 34

is performed to eliminate errors from all sources like those produced by absorption of CO2 by the alkali or by the alkalinity of the glass vessels.

Answer 34

BLANK TEST

Question 35

Defined as the number of mg of potassium hydroxide required to saponify the esters in 1 gram of fatty oil, fat, wax, balsam, resin or other similar substances

Answer 35

ESTER VALUE/ NUMBER

Question 36

Substances, which do not contain free acids, have_____ ester and saponification values.

Answer 36

equal

Question 37

Substances containing free acids have their ester values equal to the

Answer 37

difference between the acid value and saponification value.

Question 38

The ester value is important in the analysis of ____, which serves to indicate the presence of adulterants like _____

Answer 38

beeswax paraffin

Question 39

The determination of ester value of waxes is made in conjunction with the determination of the

Answer 39

ACID VALUE

Question 40

Adulterant would abnormally increase the ____ values and lowers the _____ value

Answer 40

acid ester

Question 41

These are substances that are not saponified by alkali hydroxides but are soluble in ordinary fat solvents

Answer 41

unsaponifiable matter

Question 42

After the saponification of oils and fats a small amount of residue is left consisting of ______ if the oils or fats are of vegetable origin and _____ if they are of animal origin.

Answer 42

phytosterol cholesterol

Question 43

Determination of this constant will indicate the presence of unsaponifiable adulterants such as petroleum oil added to linseed oil.

Answer 43

Unsaponifiable Matter

Question 44

Defined as the number of grams of iodine absorbed under specified condition by 100 grams of oil, fat, wax or other substance.

Answer 44

Iodine Value

Question 45

This value is a quantitative measure of the proportion of unsaturated fatty acids present both free and combined

Answer 45

iodine value

Question 46

Linseed, cod iodine value

Answer 46

>120

Question 47

Cottonseed, sesame iodine value

Answer 47

100-120

Question 48

Olive, almond iodine value

Answer 48

<100

Question 49

In conjunction with the saponification value of a fat or oil, iodine value also serves as a means of detecting

Answer 49

adulteration

Question 50

Method I

Answer 50

Hanus method – Iodobromide, CHCl3

Question 51

Method II

Answer 51

Wijs method – Iodochloride, CCl4

Question 52

is used to prevent other side reaction from taking place in which iodine monochloride is consumed.

Answer 52

iodine flask

Question 53

Defined as the number of milligrams of potassium hydroxide equivalent to the hydroxyl content of one gram of the substance.

Answer 53

hydroxyl value

Question 54

hydroxyl value constant gives an indication of the identity and purity of fatty substances possessing ______

Answer 54

alcoholic hydroxyl groups

Question 55

An abnormally low hydroxyl value is indicative of _____ with higher molecular weight alcohols or with non-alcoholic fatty substances

Answer 55

adulteration

Question 56

It is expressed as the number of mg of potassium hydroxide required to neutralize the acetic acid obtained by the saponification of 1 gram of acetylated fatty acids.

Answer 56

acetyl value

Question 57

The Acetyl Value corresponds closely to the ______ of fatty alcohol and the two constants have much the same significance with respect to identity and purity of substances

Answer 57

hydroxyl value

Question 58

Acetyl Value of Fatty Acids ❖ The acetyl value is determined by acetylating ____ e.g hydroxystearic acid or hydrogenated castor oil and determining the saponification value of the product ACETYLATED SAMPLE

Answer 58

hydroxy fatty acids

Question 59

From the saponification value of acetylated fatty acid and acid value of the original fatty acid, ____ is determined

Answer 59

acetyl value

Question 60

defined as the reactive oxygen contents expressed in terms of milliequivalents (meq) of free iodine per kg of fat

Answer 60

peroxide value (POV)

Question 61

a measure of the aldehyde levels in an oil or fat, in particular those that are unsaturated (and principally the 2–alkenals)

Answer 61

anisidine value (AnV)

Question 62

Combined PV and Anisidine value (2PV + AV)

Answer 62

Total oxidation Value (TotOx)

Question 63

Congealing point

Answer 63

Solidification Temperature of FA

Question 64

mEq of iodine

Answer 64

0.127

Question 65

mEq in mg of KOH

Answer 65

56.11