Organic compounds
-----derivatives of the
hydrocarbon
Derivatives of the hydrocarbons are
formed,by replacing one or more
hydrogen atoms by other groups referred
to as functional groups.
An alcohol is closely related to a
hydrocarbon in that it contains an OH
group in place of a hydrogen atom,Thus,
methyl alcohol,CH3OH,is a derivative of
methane,CH4; and ethyl alcohol,
C2H5OH,is a derivative of ethane,C2H6
Alcohols,R-OH
Although all alcohols have one or more
OH groups,they differ from bases such
as sodium hydroxide and potassium
hydroxide in that they do not furnish
hydroxide ions in water,not do they
have the other usual properties of
bases.
Methyl alcohol (methanol) produced
today is synthesized from either carbon
monoxide or carbon dioxide,
Methyl alcohol is a colorless liquid boiling at
65℃,In odor and taste it is similar to ethyl
alcohol,Methyl alcohol is very poisonous,
however; intoxication,blindness,and death may
result when its vapors are breathed in quantities
or when the liquid is taken internally.
Methyl alcohol is used in the manufacture of
formaldehyde and other organic products; as a
solvent for resins,gums,and shellac; and as a
denaturant for ethyl alcohol (to make the ethyl
alcohol unfit for human consumption).
Ethyl alcohol,C2H5OH,is the most important of
the alcohols,It is also known as grain alcohol,
ethanol,or simply as alcohol,It has long been
prepared from starch,cellulose,and sugars of
certain plants by the process of fermentation.
Solutions of alcohol resulting from fermentation
contain from 8 to 12 per cent alcohol,but by
fractional distillation 95 per cent alcohol can be
obtained,Removal of the residual water by
distillation over calcium oxide or barium oxide
results in the production of absolute alcohol
(100%),
Large quantities of ethyl alcohol are produced
synthetically from both ethylene or acetylene.
Ethyl alcohol is a colorless liquid with a
characteristic and somewhat pleasant odor,It is
miscible with water in all proportions,The boiling
point of the pure alcohol is 78.37℃,but it forms a
constant-boiling mixture with water that contains
95.57℃ per cent alcohol by weight and boils at
78.15℃,Ethyl alcohol is the least toxic of all the
alcohols and is present in all alcoholic beverages.
Of all synthetic compounds,ethyl alcohol ranks
first in quantity produced and economic value,It
is used as a solvent in the preparation of
tinctures,essences,extracts and varnishes,It is
used in the preparation of iodoform,ether,
medicinals,dyes,perfumes,collodion,and
solvents for the lacquer industry,It is used to
some extent as a motor fuel and is currently
under study as an additive to gasolines
containing no tetraethyl lead to increase the
octane rating.
Alcohols containing two or more hydroxyl
groups can be made,Ethylene glycol,
C2H4(OH)2,and glycerol,C3H5(OH)3,are
important examples.
Ethylene glycol is used as a solvent and
as an antifreeze in automobile radiators,
Glycerol (also called glycerin) is
produced,along with soap,when either
fats or oils are heated with alkali.
Phenols,
Derivatives of benzene which contain one or more
hydroxyl group attached directly to carbon atoms of the
benzene ring are called phenols,The hydroxyl group in
these compounds is markedly acidic in character,and
phenol itself,C6H5OH,is commonly known as carbolic
acid,It is an important constituent of coal tar but is
produced synthetically from benzene,When pure,
phenol is a colorless crystalline substance,melting at
42~43℃ and boiling at 181.4℃,It has a very corrosive
action on tissues,and on the skin it causes blisters to
form rapidly,If taken internally,phenol causes irritation
and necrosis of the mucous membranes,It may also
paralyze the central nervous system,causing death,
Very dilute solutions of phenol are used as disinfectants.
Ethers,R-O-R
The ethers are compounds obtained from
alcohols,by the elimination of a molecule
of water from two molecules of the
alcohol,For example,when ethyl alcohol
is treated with a limited amount of sulfuric
acid and heated to 140℃,diethyl ether
(ordinary ether) is formed in a series of
reactions which result also in the
formation of water.
In the general formula for ethers,R-O-R,
the hydrocarbon radicals (R) may be the
same or different,Diethyl ether is the most
important compound of this class,It is a
colorless volatile liquid (boiling point 35℃ ),
and highly flammable as a vapor,It has
been used since 1846 as an anesthetic,
Diethyl ether and other ethers are valuable
solvents for gums,fats,waxes,and resins.
Aldehydes,
The alcohols represent the first stage of
oxidation of hydrocarbons,Further oxidation
leads to the production of compounds
containing the group,-CHO,These compounds
are known as Aldehydes,When a mixture of
methyl alcohol and air is passed through a
heated tube containing either silver or a mixture
of iron powder and molybdenum oxide,an
aldehyde called formaldehyde is formed.
Formaldehyde,HCHO,is a colorless gas with a pungent
and irritating odor; it is soluble in water in all proportions,
Formaldehyde is sold in an aqueous solution which
contains about 37~37.5per cent of formaldehyde by weight
and is known as formalin,The solution also contains 7 per
cent of methyl alcohol,which is added to inhibit the reaction
of formaldehyde molecules with each other to form an
insoluble polymer (compound of high molecular weight),
The formaldehyde polymer is Bakelite,an important
material which makes formaldehyde an industrially
important compound,Formaldehyde causes coagulation of
proteins,making it useful as a preservation of anatomical
specimens and in embalming fluids,It is also useful as a
disinfectant and as a reducing agent in the production of
silvered mirrors.
Acetaldehyde,CH3CHO,is a liquid that
boils at 20.2℃,It is colorless,water soluble,
and has an odor like that of freshly out
green apples,It is used in the manufacture
of aniline dyes,synthetic rubber,and other
organic materials,
Ketones
Ketones resemble aldehydes in certain respects,since
both contain the carbonyl group C=O,In fact,a ketone
may be regarded as an aldehyde in which the hydrogen
in the aldehyde group is replaced by a hydrocarbon
radical,In the general structural formula for ketones the
R groups may be the same or different,Dimethyl ketone,
CH3COCH3 commonly called acetone,is the simplest
and most important ketone,It is made commercially by
the fermentation of corn or molasses,or by the oxidation
of petroleum gases,It is also one of the products of the
destructive distillation of wood,Acetone is a colorless
liquid boiling at 56.5℃ and possessing a characteristic
pungent odor and a sweet taste,Among the many uses
of acetone are,as a solvent for cellulose acetate,
cellulose nitrate,acetylene,plastics,and varnishes; as a
remover of paints,varnishes,and fingernail polish; and
as a solvent in the manufacture of drugs,chemicals,
smokeless powder,and the high explosive cordite.
Acids
The carboxyl group,-COOH,is characteristic of
organic acids,In general,the carboxylic acids
are weak acids,yet they readily form metallic
salts.
The simplest carboxylic acid is formic acid,
HCOOH,which was first obtained in 1670 by
the distillation of red ants,and its name was
derived from the Latin word formicus for ant,It
is partially responsible for the irritation of ant
bites and bee stings.
Acetic acid
CH3COOH,constitutes 3 to 6 per cent pf vinegar,
Cider vinegar is produced by allowing cider (apple juice)
to ferment,causing the sugar present to change to ethyl
alcohol,Then certain bacteria present in the juice
produce an enzyme that catalyzes the air oxidation of the
alcohol to acetic acid,Pure,anhydrous acetic acid is a
liquid boiling at 118.1℃,It freezes at 16.6℃ forming a
solid resembling ice in appearance; for this reason the
pure acid is usually called glacial acetic acid,Acetic acid
has a penetrating odor and a sour taste,and produces
painful burns on the skin,It is an excellent solvent for
many organic compounds and some inorganic
compounds,In addition to its use as a solvent,acetic acid
is essential in the production of cellulose acetate and has
wide application in the textile and rubber industries.
Oxalic acid
Oxalic acid is a dicarboxylic acid
represented by the formula (COOH)2 or
H2C2O2,Its molecule consists of two
carboxyl groups (dicarboxylic) bonded
together.
Oxalic acid is a colorless crystalline solid,
which is found as metal hydrogen salt in
sorrel,rhubarb,and other plants to which
it imparts a sour taste,In concentrated
form it is poisonous.
Lactic acid
Lactic acid contains a hydroxyl group as
well as a carboxyl group,and has the
structural formula shown,This acid is
produced by the fermentation of milk
sugar or glucose and is the substance
that imparts the sour taste to sour milk.
Benzoic acid
Benzoic acid C6H5COOH,is a colorless
crystalline solid with the cyclic structural formula
shown,It is a monocarboxylic acid that occurs in
cranberries and coal tar,The sodium salt of
benzoic acid is used in the preservation of certain
foods,such as tomato ketchup and fruit juices.
A type of organic acid commonly called a fatty
acid,since this type of acid is commonly obtained
from fats,results when a carboxyl group replaces
one of the hydrogen atoms in a molecular weight
hydrocarbon,Examples are palmitic acid
(C15H31COOH),stearic acid (C17H35COOH),and
oleic acid (C17H33COOH).
Esters
Esters are the products of reaction of
acids with alcohols,For example,the
ester ethyl acetate,CH3COOC2H5,is
formed when acetic acid reacts with ethyl
alcohol.
This reaction is similar to that between
acetic acid and sodium hydroxide,
whereby the salt sodium acetate,
CH3COONa,is formed.
However,esters differ from metallic salts of
organic acids in that,generally speaking,
esters are volatile liquids with a pleasing
odor,they are not ionized,and they are
soluble in organic solvents but not in water,
The distinctive and attractive odors and
flavors of many flowers and ripe fruits are
due to the presence of one or more esters,
Among the most important of the natural
esters are fats (such as lard,tallow,and
butter) and oils (such as linseed,
cottonseed,and olive),Fats and oils are
esters of the trihydroxyl alcohol glycerol,
C3H5(OH)3,utilizing such high molecular
weight acids as palmitic,C15H31COOH,
stearic,C17H35COOH,and oleic,
C17H33COOH.
-----derivatives of the
hydrocarbon
Derivatives of the hydrocarbons are
formed,by replacing one or more
hydrogen atoms by other groups referred
to as functional groups.
An alcohol is closely related to a
hydrocarbon in that it contains an OH
group in place of a hydrogen atom,Thus,
methyl alcohol,CH3OH,is a derivative of
methane,CH4; and ethyl alcohol,
C2H5OH,is a derivative of ethane,C2H6
Alcohols,R-OH
Although all alcohols have one or more
OH groups,they differ from bases such
as sodium hydroxide and potassium
hydroxide in that they do not furnish
hydroxide ions in water,not do they
have the other usual properties of
bases.
Methyl alcohol (methanol) produced
today is synthesized from either carbon
monoxide or carbon dioxide,
Methyl alcohol is a colorless liquid boiling at
65℃,In odor and taste it is similar to ethyl
alcohol,Methyl alcohol is very poisonous,
however; intoxication,blindness,and death may
result when its vapors are breathed in quantities
or when the liquid is taken internally.
Methyl alcohol is used in the manufacture of
formaldehyde and other organic products; as a
solvent for resins,gums,and shellac; and as a
denaturant for ethyl alcohol (to make the ethyl
alcohol unfit for human consumption).
Ethyl alcohol,C2H5OH,is the most important of
the alcohols,It is also known as grain alcohol,
ethanol,or simply as alcohol,It has long been
prepared from starch,cellulose,and sugars of
certain plants by the process of fermentation.
Solutions of alcohol resulting from fermentation
contain from 8 to 12 per cent alcohol,but by
fractional distillation 95 per cent alcohol can be
obtained,Removal of the residual water by
distillation over calcium oxide or barium oxide
results in the production of absolute alcohol
(100%),
Large quantities of ethyl alcohol are produced
synthetically from both ethylene or acetylene.
Ethyl alcohol is a colorless liquid with a
characteristic and somewhat pleasant odor,It is
miscible with water in all proportions,The boiling
point of the pure alcohol is 78.37℃,but it forms a
constant-boiling mixture with water that contains
95.57℃ per cent alcohol by weight and boils at
78.15℃,Ethyl alcohol is the least toxic of all the
alcohols and is present in all alcoholic beverages.
Of all synthetic compounds,ethyl alcohol ranks
first in quantity produced and economic value,It
is used as a solvent in the preparation of
tinctures,essences,extracts and varnishes,It is
used in the preparation of iodoform,ether,
medicinals,dyes,perfumes,collodion,and
solvents for the lacquer industry,It is used to
some extent as a motor fuel and is currently
under study as an additive to gasolines
containing no tetraethyl lead to increase the
octane rating.
Alcohols containing two or more hydroxyl
groups can be made,Ethylene glycol,
C2H4(OH)2,and glycerol,C3H5(OH)3,are
important examples.
Ethylene glycol is used as a solvent and
as an antifreeze in automobile radiators,
Glycerol (also called glycerin) is
produced,along with soap,when either
fats or oils are heated with alkali.
Phenols,
Derivatives of benzene which contain one or more
hydroxyl group attached directly to carbon atoms of the
benzene ring are called phenols,The hydroxyl group in
these compounds is markedly acidic in character,and
phenol itself,C6H5OH,is commonly known as carbolic
acid,It is an important constituent of coal tar but is
produced synthetically from benzene,When pure,
phenol is a colorless crystalline substance,melting at
42~43℃ and boiling at 181.4℃,It has a very corrosive
action on tissues,and on the skin it causes blisters to
form rapidly,If taken internally,phenol causes irritation
and necrosis of the mucous membranes,It may also
paralyze the central nervous system,causing death,
Very dilute solutions of phenol are used as disinfectants.
Ethers,R-O-R
The ethers are compounds obtained from
alcohols,by the elimination of a molecule
of water from two molecules of the
alcohol,For example,when ethyl alcohol
is treated with a limited amount of sulfuric
acid and heated to 140℃,diethyl ether
(ordinary ether) is formed in a series of
reactions which result also in the
formation of water.
In the general formula for ethers,R-O-R,
the hydrocarbon radicals (R) may be the
same or different,Diethyl ether is the most
important compound of this class,It is a
colorless volatile liquid (boiling point 35℃ ),
and highly flammable as a vapor,It has
been used since 1846 as an anesthetic,
Diethyl ether and other ethers are valuable
solvents for gums,fats,waxes,and resins.
Aldehydes,
The alcohols represent the first stage of
oxidation of hydrocarbons,Further oxidation
leads to the production of compounds
containing the group,-CHO,These compounds
are known as Aldehydes,When a mixture of
methyl alcohol and air is passed through a
heated tube containing either silver or a mixture
of iron powder and molybdenum oxide,an
aldehyde called formaldehyde is formed.
Formaldehyde,HCHO,is a colorless gas with a pungent
and irritating odor; it is soluble in water in all proportions,
Formaldehyde is sold in an aqueous solution which
contains about 37~37.5per cent of formaldehyde by weight
and is known as formalin,The solution also contains 7 per
cent of methyl alcohol,which is added to inhibit the reaction
of formaldehyde molecules with each other to form an
insoluble polymer (compound of high molecular weight),
The formaldehyde polymer is Bakelite,an important
material which makes formaldehyde an industrially
important compound,Formaldehyde causes coagulation of
proteins,making it useful as a preservation of anatomical
specimens and in embalming fluids,It is also useful as a
disinfectant and as a reducing agent in the production of
silvered mirrors.
Acetaldehyde,CH3CHO,is a liquid that
boils at 20.2℃,It is colorless,water soluble,
and has an odor like that of freshly out
green apples,It is used in the manufacture
of aniline dyes,synthetic rubber,and other
organic materials,
Ketones
Ketones resemble aldehydes in certain respects,since
both contain the carbonyl group C=O,In fact,a ketone
may be regarded as an aldehyde in which the hydrogen
in the aldehyde group is replaced by a hydrocarbon
radical,In the general structural formula for ketones the
R groups may be the same or different,Dimethyl ketone,
CH3COCH3 commonly called acetone,is the simplest
and most important ketone,It is made commercially by
the fermentation of corn or molasses,or by the oxidation
of petroleum gases,It is also one of the products of the
destructive distillation of wood,Acetone is a colorless
liquid boiling at 56.5℃ and possessing a characteristic
pungent odor and a sweet taste,Among the many uses
of acetone are,as a solvent for cellulose acetate,
cellulose nitrate,acetylene,plastics,and varnishes; as a
remover of paints,varnishes,and fingernail polish; and
as a solvent in the manufacture of drugs,chemicals,
smokeless powder,and the high explosive cordite.
Acids
The carboxyl group,-COOH,is characteristic of
organic acids,In general,the carboxylic acids
are weak acids,yet they readily form metallic
salts.
The simplest carboxylic acid is formic acid,
HCOOH,which was first obtained in 1670 by
the distillation of red ants,and its name was
derived from the Latin word formicus for ant,It
is partially responsible for the irritation of ant
bites and bee stings.
Acetic acid
CH3COOH,constitutes 3 to 6 per cent pf vinegar,
Cider vinegar is produced by allowing cider (apple juice)
to ferment,causing the sugar present to change to ethyl
alcohol,Then certain bacteria present in the juice
produce an enzyme that catalyzes the air oxidation of the
alcohol to acetic acid,Pure,anhydrous acetic acid is a
liquid boiling at 118.1℃,It freezes at 16.6℃ forming a
solid resembling ice in appearance; for this reason the
pure acid is usually called glacial acetic acid,Acetic acid
has a penetrating odor and a sour taste,and produces
painful burns on the skin,It is an excellent solvent for
many organic compounds and some inorganic
compounds,In addition to its use as a solvent,acetic acid
is essential in the production of cellulose acetate and has
wide application in the textile and rubber industries.
Oxalic acid
Oxalic acid is a dicarboxylic acid
represented by the formula (COOH)2 or
H2C2O2,Its molecule consists of two
carboxyl groups (dicarboxylic) bonded
together.
Oxalic acid is a colorless crystalline solid,
which is found as metal hydrogen salt in
sorrel,rhubarb,and other plants to which
it imparts a sour taste,In concentrated
form it is poisonous.
Lactic acid
Lactic acid contains a hydroxyl group as
well as a carboxyl group,and has the
structural formula shown,This acid is
produced by the fermentation of milk
sugar or glucose and is the substance
that imparts the sour taste to sour milk.
Benzoic acid
Benzoic acid C6H5COOH,is a colorless
crystalline solid with the cyclic structural formula
shown,It is a monocarboxylic acid that occurs in
cranberries and coal tar,The sodium salt of
benzoic acid is used in the preservation of certain
foods,such as tomato ketchup and fruit juices.
A type of organic acid commonly called a fatty
acid,since this type of acid is commonly obtained
from fats,results when a carboxyl group replaces
one of the hydrogen atoms in a molecular weight
hydrocarbon,Examples are palmitic acid
(C15H31COOH),stearic acid (C17H35COOH),and
oleic acid (C17H33COOH).
Esters
Esters are the products of reaction of
acids with alcohols,For example,the
ester ethyl acetate,CH3COOC2H5,is
formed when acetic acid reacts with ethyl
alcohol.
This reaction is similar to that between
acetic acid and sodium hydroxide,
whereby the salt sodium acetate,
CH3COONa,is formed.
However,esters differ from metallic salts of
organic acids in that,generally speaking,
esters are volatile liquids with a pleasing
odor,they are not ionized,and they are
soluble in organic solvents but not in water,
The distinctive and attractive odors and
flavors of many flowers and ripe fruits are
due to the presence of one or more esters,
Among the most important of the natural
esters are fats (such as lard,tallow,and
butter) and oils (such as linseed,
cottonseed,and olive),Fats and oils are
esters of the trihydroxyl alcohol glycerol,
C3H5(OH)3,utilizing such high molecular
weight acids as palmitic,C15H31COOH,
stearic,C17H35COOH,and oleic,
C17H33COOH.
