More on carboxylic acids, esters and fatty acids

Question 1

in aqueous solution, the cleavage of O-H bonds result in the formation of ___________ and ______________

Answer 1

Carboxylate ion and hydronium ion

Question 2

are carboxylic acids weak or strong acids?

Answer 2

weak acids

Question 3

true or false

Carboxylic acids ionize fully.

Answer 3

False. An equilibrium exists between the ionized and unionized forms.

Question 4

Carboxylic acids react with active metals to form what?

Answer 4

Salts and hydrogen gas.

Question 5

How do we name the salts of carboxylic acids?

Answer 5

named by writing the metal first and then replacing the “-ic acid” with “-ate”

Question 6

Carboxylic acids react with strong bases like sodium hydroxide or potassium hydroxide to form what?

Answer 6

Salts and water.

Question 7

Carboxylic acids react with weak bases like carbonates or bicarbonates to form what?

Answer 7

salt, water and carbon dioxide.

Question 8

carboxylic acids react with ammonia to form ____________

Answer 8

ammonium salts of carboxylic acids

Question 9

The reaction where the -OH group is replaced by an alkoxy group to form esters is called

Answer 9

Esterification

Question 10

One of the important methods for preparation of carboxylic acids is _______

Answer 10

oxidation

Question 11

the primary alcools are readily oxidized to the corresponding carboxylic acids by their reaction with common oxidizing agents like ________

Answer 11

potassium permanagate or potassium dichromate

Question 12

true or false

The alkyl group, in the oxidation of alkylbenzenes, is oxidised to carboxyl group irresptive of its size.

Answer 12

True

for example, toluene and ethylbenzene both give benzoix acid on refluxing with KMnO4 in alkaline medium.

Question 13

____________ is one of the important carboxylix acids which is used as food preservaive.

Answer 13

Acetic acid

Question 14

The process in which large quantities of acetic acid is obtained in industry from fermentation of ethanol is known as ________>

Answer 14

Quick Vinegar Fermentation Process

gives 10% yield

Question 15

what do we call the carboxylic acids with a long hydrocarbon chain?

Answer 15

Fatty acids

Question 16

Which one is more saturated? Animal fatty acids or vegetable origin fatty acids?

Answer 16

Animal fatty acids

Question 17

True or False

Most fatty acids contain an even number of carbon atoms

Answer 17

True

With only a few exceptions, fatty acids are straight chain compounds

Question 18

Fatty acids that do not contaion carbon-carbon double bonds are known as ________

Answer 18

saturated fatty acids

Question 19

Fatty acids thhat contain one or more double bonds are called ____—

Answer 19

unsaturated acids

Question 20

Name the carboxylic formula

CH3(CH2)10COOH

Answer 20

Lauric acids

Question 21

Name the formula

CH3(CH2)12COOH

Answer 21

Myristic acid

Question 22

Name the formula

CH3(CH2)14COOH

Answer 22

Palmitic acid

Question 23

Name the formula

CH3(CH2)16COOH

Answer 23

Stearic acid

Question 24

Name the formula

CH3(CH2)18COOH

Answer 24

Archaric acid

Question 25

state some uses of the acetic acid

Answer 25

* as a solvent * as a starting material in the prep of acetaes, acetic anhydride * used to prepare vinyl acetate polymer(for paints) * used to prepare **Asprin** by reacting salicyclic acid(*2-hydroxylbenoic acid*)

Question 26

# true or false the smell of esters is usually unpleasant

Answer 26

False

Question 27

____________ are derivatives of carboxylic acids in which the hydroxyl group of carboxylic acid has been replaced by an alkoxy group

Answer 27

Esters

Question 28

# True or false When naming esters, the first part comes from the protion of the alchohol

Answer 28

true | the second portions is based on the carboxylic acids

Question 29

the portion coming from alcohol is attaced to the oxygen as an ________ and the acid portion is attached to the oxygen through ___________

Answer 29

alkyl group, carbonyl group

Question 30

# True or false Molecular formula can represent more than one structure.

Answer 30

True ## Footnote for C3O2H6, it can be Methyl ethanoate or Ethyl methanoate

Question 31

Does the boiling point of ester increase or decrease with increasing molecular mass?

Answer 31

increase

Question 32

can ester molecules form hydrogen bonds with each other?

Answer 32

No, they cannot. But they can form hydrogen bonding with water

Question 33

Do esters have lower or higher boiling points than carboxylic acids and alcohols or comparable molecular mass?

Answer 33

Lower boiling points since they cannot form hydrogen bonding with each other.

Question 34

is the solubility of esters in water about the same as that of carboxylic acids of the same molecular mass?

Answer 34

Yes. Because they can have hydrogen bonding with water

Question 35

are esters soluble in inorganic solvents?

Answer 35

no, they are soluble in organic solvents

Question 36

Hydrolysis of esters in the presence of an acid catalyst yield in __________

Answer 36

carboxylic acids and alcohols

Question 37

Hydrolysis of esters in base catalysed reaction yields in __________

Answer 37

salts of carboxylic acids and alcohols

Question 38

Base catalyzed ester hydrolysis is called

Answer 38

saponification | generally uses **sodium hydroxide** or **potassium hydroxide**

Question 39

in reduction reactions, esters are reduced to ________

Answer 39

alchohols | uses reducing agents like lithium aluminum hydride

Question 40

in esterification, carboxylic acids and alchohols are heated to make ester in the presence of which catalyst?

Answer 40

sulphuric acid. | with the elimination of water

Question 41

name some properties of esters of small acids and alcohol

Answer 41

1. non corrosive 2. non-toxic 3. good solvents for oils and fats, nail polishes,varnishes, paints, gums, resins

Question 42

name some uses of esters

Answer 42

1. solvents 2. edicine 3. clothing 4. fragnances in perfume

Question 43

# name the ester present in the following fruit Apple

Answer 43

Ethyl isovalerate

Question 44

# name the ester present in the following fruits Pineapple

Answer 44

Methyl butanoate and ethyl butanoate

Question 45

# name the ester found in the following fruit Banana

Answer 45

Isopentyl acetate

Question 46

# name the ester present in the fruit Orange

Answer 46

Octyl acetate

Question 47

fats and oils belong to a class of biomolecules called ________

Answer 47

lipids

Question 48

fats and oils are triesters of glycerol which are collectlively known as _______________-

Answer 48

triglycerides or triacylglycerols

Question 49

the distinction between a fat and an oil depends upon their _______

Answer 49

physical states

Question 50

If the substance is solid or semi solid at ordinary temperature, it is termed _____

Answer 50

fat

Question 51

List three examples of marine fats

Answer 51

liver oil, blubber oil, fish oil.

Question 52

# choose one. variation in the structure of fats and oils occur in the acid/alcohol protion

Answer 52

acid portion

Question 53

# true or false fats are mostly ester of glycerol and unsaturated fatty acids while oils are liquid ester derived form saturated faty acids and glycerol

Answer 53

False. Fats come from saturated fatty acids andoils come from unsaturated fatty acids

Question 54

state some common physical properties of fats and oils

Answer 54

1. greasy to the touch 2. have lubricating properties 3. not readily volatile 4. burned without no residue 5. colorless 6. odorless 7. neutral substance in pure state 8. lighter than water and immiscible in it

Question 55

# choose butter lard, tarrow are liquids/solids in room temperature

Answer 55

solids

Question 56

oils can be converted to fats by a process called ________

Answer 56

hardening of oils ## Footnote additionof hydrogen at high pressure in the presence of nickel or palladum

Question 57

____ are sodium or potassium salts of long chain fatty acids.

Answer 57

soaps