More on carboxylic acids, esters and fatty acids Flashcards
in aqueous solution, the cleavage of O-H bonds result in the formation of ___________ and ______________
Carboxylate ion and hydronium ion
are carboxylic acids weak or strong acids?
weak acids
true or false
Carboxylic acids ionize fully.
False. An equilibrium exists between the ionized and unionized forms.
Carboxylic acids react with active metals to form what?
Salts and hydrogen gas.
How do we name the salts of carboxylic acids?
named by writing the metal first and then replacing the “-ic acid” with “-ate”
Carboxylic acids react with strong bases like sodium hydroxide or potassium hydroxide to form what?
Salts and water.
Carboxylic acids react with weak bases like carbonates or bicarbonates to form what?
salt, water and carbon dioxide.
carboxylic acids react with ammonia to form ____________
ammonium salts of carboxylic acids
The reaction where the -OH group is replaced by an alkoxy group to form esters is called
Esterification
One of the important methods for preparation of carboxylic acids is _______
oxidation
the primary alcools are readily oxidized to the corresponding carboxylic acids by their reaction with common oxidizing agents like ________
potassium permanagate or potassium dichromate
true or false
The alkyl group, in the oxidation of alkylbenzenes, is oxidised to carboxyl group irresptive of its size.
True
for example, toluene and ethylbenzene both give benzoix acid on refluxing with KMnO4 in alkaline medium.
____________ is one of the important carboxylix acids which is used as food preservaive.
Acetic acid
The process in which large quantities of acetic acid is obtained in industry from fermentation of ethanol is known as ________>
Quick Vinegar Fermentation Process
gives 10% yield
what do we call the carboxylic acids with a long hydrocarbon chain?
Fatty acids
Which one is more saturated? Animal fatty acids or vegetable origin fatty acids?
Animal fatty acids
True or False
Most fatty acids contain an even number of carbon atoms
True
With only a few exceptions, fatty acids are straight chain compounds
Fatty acids that do not contaion carbon-carbon double bonds are known as ________
saturated fatty acids
Fatty acids thhat contain one or more double bonds are called ____—
unsaturated acids
Name the carboxylic formula
CH3(CH2)10COOH
Lauric acids
Name the formula
CH3(CH2)12COOH
Myristic acid
Name the formula
CH3(CH2)14COOH
Palmitic acid
Name the formula
CH3(CH2)16COOH
Stearic acid
Name the formula
CH3(CH2)18COOH
Archaric acid
state some uses of the acetic acid
- 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)
true or false
the smell of esters is usually unpleasant
False
____________ are derivatives of carboxylic acids in which the hydroxyl group of carboxylic acid has been replaced by an alkoxy group
Esters
True or false
When naming esters, the first part comes from the protion of the alchohol
true
the second portions is based on the carboxylic acids
the portion coming from alcohol is attaced to the oxygen as an ________ and the acid portion is attached to the oxygen through ___________
alkyl group, carbonyl group
True or false
Molecular formula can represent more than one structure.
True
for C3O2H6, it can be Methyl ethanoate or Ethyl methanoate
Does the boiling point of ester increase or decrease with increasing molecular mass?
increase
can ester molecules form hydrogen bonds with each other?
No, they cannot.
But they can form hydrogen bonding with water
Do esters have lower or higher boiling points than carboxylic acids and alcohols or comparable molecular mass?
Lower boiling points since they cannot form hydrogen bonding with each other.
is the solubility of esters in water about the same as that of carboxylic acids of the same molecular mass?
Yes. Because they can have hydrogen bonding with water
are esters soluble in inorganic solvents?
no, they are soluble in organic solvents
Hydrolysis of esters in the presence of an acid catalyst yield in __________
carboxylic acids and alcohols
Hydrolysis of esters in base catalysed reaction yields in __________
salts of carboxylic acids and alcohols
Base catalyzed ester hydrolysis is called
saponification
generally uses sodium hydroxide or potassium hydroxide
in reduction reactions, esters are reduced to ________
alchohols
uses reducing agents like lithium aluminum hydride
in esterification, carboxylic acids and alchohols are heated to make ester in the presence of which catalyst?
sulphuric acid.
with the elimination of water
name some properties of esters of small acids and alcohol
- non corrosive
- non-toxic
- good solvents for oils and fats, nail polishes,varnishes, paints, gums, resins
name some uses of esters
- solvents
- edicine
- clothing
- fragnances in perfume
name the ester present in the following fruit
Apple
Ethyl isovalerate
name the ester present in the following fruits
Pineapple
Methyl butanoate and ethyl butanoate
name the ester found in the following fruit
Banana
Isopentyl acetate
name the ester present in the fruit
Orange
Octyl acetate
fats and oils belong to a class of biomolecules called ________
lipids
fats and oils are triesters of glycerol which are collectlively known as _______________-
triglycerides or triacylglycerols
the distinction between a fat and an oil depends upon their _______
physical states
If the substance is solid or semi solid at ordinary temperature, it is termed _____
fat
List three examples of marine fats
liver oil, blubber oil, fish oil.
choose one.
variation in the structure of fats and oils occur in the acid/alcohol protion
acid portion
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
False. Fats come from saturated fatty acids andoils come from unsaturated fatty acids
state some common physical properties of fats and oils
- greasy to the touch
- have lubricating properties
- not readily volatile
- burned without no residue
- colorless
- odorless
- neutral substance in pure state
- lighter than water and immiscible in it
choose
butter lard, tarrow are liquids/solids in room temperature
solids
oils can be converted to fats by a process called ________
hardening of oils
additionof hydrogen at high pressure in the presence of nickel or palladum
____ are sodium or potassium salts of long chain fatty acids.
soaps
