Carboxylic acids Flashcards
What is the prefix for carboxylic acids?
anoic acid
What is the prefix for a compound with 2 carboxylic acid func groups?
dioc acid
What state are carboxylic acids at room temp?
liquid
Which has a higher BP an alcohol or a carboxylic acid? and why?
higher in a carboxylic acid = carboxylic acid is more polar than alcohol so permenant d-d forces
and carboxylics have a structure which allows them to form more H bonds
Are carboxylic acids soluble in water?
yes = they form H bonds
What affects the solubility of carboxylic acids in water?
the longer the hydrocarbon chain, solubility decreases = it is non-polar
this can outweigh the polar OH group
Are carboxylic acids strong or weak acids?
weak = only slightly soluble in aq solution
What is a derivative?
a compound in which the functional group of a compound is converted into something different
What are all the derivatives of carboxylic acids?
esthers
acyl chlorides
acid anhydrides
amides
What is the functional group of esthers?
RCOOR
What is the name ending for esthers?
anoate
Do esthers have a lower or higher MP and BP than carboxylic acids?
lower
esthers only form permanent d-d and induced
carboxylic acids form H bonds
How can you make an esther from a carboxylic acid? What is the process called?
Esterification of a carboxylic acid with an alcohol
adding an alcohol to a carboxylic acid
condensation reaction
What is the general reaction of esterification of a carboxylic acid with an alcohol?
carboxylic acid + alcohol —> ester + water
What type of reaction is esterification?
condensation = water molecule is removed
What are the conditions for esterification?
conc H2SO4 and heat
reflux
What are acid anhydrides?
compunds formed by the dehydration of carboxylic acids
What is the general formula of acid anhydrides?
RCOOCOR
Carbon double bonded to an O with an R group
bonded to an O that is bonded to another Carbon double bonded to an O with an R group
How do you name acid anhydrides?
anoic anhydride
How is an acid anhydride formed?
formed from 2 carboxylic acids by the elimination of water
How do you form an ester from an acid anhydride?
anhydride and alcohol makes an ester and carboxylic acid
what is the equation reacting an acid anhydride with an alcohol?
anhydride + alcohol —> ester + carboxylic acid
What is the condition for reacting an acid anhydride with an alcohol?
gentle heat
no catalyst
What are the advantages of producing esters from acid anhydrides rather than carboxylic acids?
milder conditions = stong acid catalyst needed for carboxylic reaction which might cause further reaction of other functional groups
reaction with acid anhydrides is irreversible = easier to get a higher yield of ester using anhydride
What is a hydrolysis reaction?
a reaction which a compound is broken down by addition of a water molecule
What reacts with an ester in base catalysed hydrolysis?
NaOH - for OH-
What does base catalysed hydrolysis form?
alcohol and the salt of the carboxylic acid
What are the conditions of base hydrolysis of an ester?
refulx with aq NaOH
Why is base catalysed hydrolysis better than hydrolysing a ester with water?
irreversible reaction so it gives higher yields
How do you convert the carboxylic salt into its carboxylic acid?
neutralise with aq acid
distill off the carboxylic acid
What are the 2 types of hydrolysis?
acid catalysed
base catalysed
What are the products of base catalysed hydrolysis?
salt and alcohol
Why does acid catalysed hydrolysis produce a lower yield?
it is reversible
What are the conditions for acid catalysed hydrolysis?
reflux with aq HCl
What are the uses of esters?
simple (low mr) esters are volatile and have pleasant, fruity smells which are used in flavourings and perfumes
What are acyl chlorides?
carboxylic derivative which the OH group is replaced with a Cl
How do you name acyl chlorides?
oyl chloride
How do you make acyl chlorides?
use the parent carboxylic acid with SOCl2
What is SOCL2 called?
thionyl chloride
Why are acyl chlorides used in synthesis?
they are very reactive because the chlorine readily leaves as Cl- to be replaced by other groups
What are the 2 reactions of acyl chlorides you need to know?
Friedel-Crafts acylation - halogen carrier and aromatic compound
adding an alcohol to form an ester
How can esters be made from acyl chlorides?
add an alcohol to form ester and HCl
What are the advanatges of making on ester from acyl chloride than estrifying a carboxylic acid?
reaction with acyl chlorides happens more rapidly
no catalyst needed and no heat
high yield
used to esterify phenols which will not directly react with carboxylic acids to form phenol esters6+
How can acyl chlorides be converted into carboxylic acids?
add water to acyl chloride to produce carboxylic and HCl
How can acyl chlorides form amides?
acyl chlorides react with ammonia to make amines to make amides
How is a carboxylic acid formed from a base hydrolysis of an ester?
add H+ to the salt
How do you remove a carboxylic acid from a solution?
if its a solid = it will precipitate out
if its oil = will form a layer of oil which needs to be separated using a separating funnel
if it’s a liquid = distillation
What are the conditions for forming an ester from a RCOOH and ROH?
heat under reflux
acid catalyst
How do you form a RCOOH from a nitrile? (conditions)
HCl, H2O and heat
