that are generally immiscible with
water. Natural plant and animal oils
are either volatile mixtures of terpenes and simple esters (e.g. *essential oils) or are *glycerides of fatty
acids. Mineral oils are mixtures of hydrocarbons (e.g. *petroleum).
oil of vitriol See sulphuric acid.
oil of wintergreen Methyl salicylate (methyl 2-hydroxybenzoate,
C 8 H 8 O 3 ), a colourless aromatic liquid
ester, b.p. 223°C. It occurs in the essential oils of some plants, and is
manufactured from salicylic acid. It is
easily absorbed through the skin and
used in medicine for treating muscular and sciatic pain. Because of its attractive smell it is also used in
perfumes and food Ûavourings.
oil sand (tar sand; bituminous sand)
A sandstone or porous carbonate
rock that is impregnated with hydrocarbons. The largest deposit of oil
sand occurs in Alberta, Canada (the
Athabasca tar sands); there are also
deposits in the Orinoco Basin of
Venezuela, Russia, USA, Madagascar,
Albania, Trinidad, and Romania.
oil shale A Üne-grained carbonaceous sedimentary rock from which
oil can be extracted. The rock contains organic matter – kerogen –
which decomposes to yield oil when
heated. Deposits of oil shale occur on
every continent, the largest known
reserves occurring in Colorado, Utah,
and Wyoming in the USA. Commercial production of oil from oil shale is
generally considered to be uneconomic unless the price of petroleum
rises above the recovery costs for oil
from oil shale. However, threats of
declining conventional oil resources
have resulted in considerable interest
and developments in recovery techniques.
oleaginous Producing or containing oil or lipids. Oleaginous microorganisms, which normally contain
20–25% oil, are of interest in biotechnology as alternative sources of conventional oils or as possible sources
for novel oils. The majority of the
oils produced by oleaginous eukaryotic microorganisms are similar to
plant oils. One possibility under consideration is the production of oils
and fats from waste material, to be
used in animal feed.
oleate A salt or ester of *oleic acid.
oleÜnes See alkenes.
oleic acid An unsaturated *fatty
acid with one double bond,
CH 3 (CH 2 ) 7 CH:CH(CH 2 ) 7 COOH; r.d. 0.9;
m.p. 13°C. Oleic acid is one of the
most abundant constituent fatty
acids of animal and plant fats, occurring in butterfat, lard, tallow,
groundnut oil, soya-bean oil, etc.
Its systematic chemical name is cisoctadec-9-enoic acid.
oleum See disulphuric(vi) acid.
oligonucleotide A short polymer
of *nucleotides.
oligopeptide See peptide.
oligosaccharide A carbohydrate (a
type of *sugar) whose molecules contain a chain of up to 20 united monosaccharides. Oligosaccharides are
formed as intermediates during the
digestion of *polysaccharides, such
as cellulose and starch.
olivine An important group of
rock-forming silicate minerals crystallizing in the orthorhombic system.
Olivine conforms to the general formula (Mg,Fe) 2 SiO 4 and comprises a
complete series from pure magnesium silicate (forsterite, Mg 2 SiO 4 ) to
pure iron silicate (fayalite, Fe 2 SiO 4 ). It
is green, brown-green, or yellowgreen in colour. A gem variety of
olivine is peridot.
one-pot synthesis A method of
383
one-pot synthesis
o
www.AzShimi.ir www.AzShimi.com
water. Natural plant and animal oils
are either volatile mixtures of terpenes and simple esters (e.g. *essential oils) or are *glycerides of fatty
acids. Mineral oils are mixtures of hydrocarbons (e.g. *petroleum).
oil of vitriol See sulphuric acid.
oil of wintergreen Methyl salicylate (methyl 2-hydroxybenzoate,
C 8 H 8 O 3 ), a colourless aromatic liquid
ester, b.p. 223°C. It occurs in the essential oils of some plants, and is
manufactured from salicylic acid. It is
easily absorbed through the skin and
used in medicine for treating muscular and sciatic pain. Because of its attractive smell it is also used in
perfumes and food Ûavourings.
oil sand (tar sand; bituminous sand)
A sandstone or porous carbonate
rock that is impregnated with hydrocarbons. The largest deposit of oil
sand occurs in Alberta, Canada (the
Athabasca tar sands); there are also
deposits in the Orinoco Basin of
Venezuela, Russia, USA, Madagascar,
Albania, Trinidad, and Romania.
oil shale A Üne-grained carbonaceous sedimentary rock from which
oil can be extracted. The rock contains organic matter – kerogen –
which decomposes to yield oil when
heated. Deposits of oil shale occur on
every continent, the largest known
reserves occurring in Colorado, Utah,
and Wyoming in the USA. Commercial production of oil from oil shale is
generally considered to be uneconomic unless the price of petroleum
rises above the recovery costs for oil
from oil shale. However, threats of
declining conventional oil resources
have resulted in considerable interest
and developments in recovery techniques.
oleaginous Producing or containing oil or lipids. Oleaginous microorganisms, which normally contain
20–25% oil, are of interest in biotechnology as alternative sources of conventional oils or as possible sources
for novel oils. The majority of the
oils produced by oleaginous eukaryotic microorganisms are similar to
plant oils. One possibility under consideration is the production of oils
and fats from waste material, to be
used in animal feed.
oleate A salt or ester of *oleic acid.
oleÜnes See alkenes.
oleic acid An unsaturated *fatty
acid with one double bond,
CH 3 (CH 2 ) 7 CH:CH(CH 2 ) 7 COOH; r.d. 0.9;
m.p. 13°C. Oleic acid is one of the
most abundant constituent fatty
acids of animal and plant fats, occurring in butterfat, lard, tallow,
groundnut oil, soya-bean oil, etc.
Its systematic chemical name is cisoctadec-9-enoic acid.
oleum See disulphuric(vi) acid.
oligonucleotide A short polymer
of *nucleotides.
oligopeptide See peptide.
oligosaccharide A carbohydrate (a
type of *sugar) whose molecules contain a chain of up to 20 united monosaccharides. Oligosaccharides are
formed as intermediates during the
digestion of *polysaccharides, such
as cellulose and starch.
olivine An important group of
rock-forming silicate minerals crystallizing in the orthorhombic system.
Olivine conforms to the general formula (Mg,Fe) 2 SiO 4 and comprises a
complete series from pure magnesium silicate (forsterite, Mg 2 SiO 4 ) to
pure iron silicate (fayalite, Fe 2 SiO 4 ). It
is green, brown-green, or yellowgreen in colour. A gem variety of
olivine is peridot.
one-pot synthesis A method of
383
one-pot synthesis
o
www.AzShimi.ir www.AzShimi.com