petroleum. Its main use is as bottled
gas for fuel.
propanedioic acid (malonic acid)
A white crystalline dicarboxylic acid,
HOOCCH 2 COOH; m.p. 132°C. It decomposes above its melting point to
ethanoic acid. Propanedioic acid is
used in the synthesis of other dicarboxylic acids.
propanoic acid (propionic acid) A
colourless liquid *carboxylic acid,
CH 3 CH 2 COOH; r.d. 0.99; m.p.
–20.8°C; b.p. 141°C. It is used to
make calcium propanate – an additive in bread.
propanol Either of two *alcohols
with the formula C 3 H 7 OH. Propan-1ol is CH 3 CH 2 CH 2 OH and propan-2-ol
is CH 3 CH(OH)CH 3 . Both are colourless volatile liquids. Propan-2-ol is
used in making propanone (acetone).
propanone (acetone) A colourless
Ûammable volatile compound,
CH 3 COCH 3 ; r.d. 0.79; m.p. –95.4°C;
b.p. 56.2°C. The simplest *ketone,
propanone is miscible with water. It
is made by oxidation of propan-2-ol
(see propanol) or is obtained as a byproduct in the manufacture of phenol from cumene; it is used as a
solvent and as a raw material for
making plastics.
propellant 1. A substance that
burns rapidly in a controlled way,
used to propel a projectile (e.g. from
a gun). In Ürearms, gunpowder and
cordite are common examples. 2. A
fuel used in a rocket engine. Usually
the propellant is a fuel and an oxidizer; for example kerosene or liquid
hydrogen with a liquid oxygen propellant. 3. A substance used to produce the spray in an aerosol can.
Aerosol propellants are volatile substances that can be liqueÜed under
pressure and are able to dissolve the
working substance. When the pressure is released, the liquid vaporizes
producing the spray. Formerly
chloroÛuorocarbons were used but
their use has been discontinued because of their effect on the ozone
layer. Most aerosol cans use liquid
hydrocarbon mixtures as the propellant.
propenal (acrolein) A colourless
pungent liquid unsaturated aldehyde,
CH 2 :CHCHO; r.d. 0.84; m.p. –87°C;
b.p. 53°C. It is made from propene
and is used in producing polyester
and polyurethane resins.
propene (propylene) A colourless
gaseous hydrocarbon, CH 3 CH:CH 2 ;
m.p. –185.25°C; b.p. –47.4°C. It is an
*alkene obtained from petroleum by
cracking alkanes. Its main use is in
the manufacture of polypropene.
propenoate (acrylate) A salt or
ester of *propenoic acid.
propenoic acid (acrylic acid) An
unsaturated liquid *carboxylic acid,
CH 2 :CHCOOH; m.p. 13°C; b.p.
141.6°C. It readily polymerizes and it
is used in the manufacture of
*acrylic resins.
propenol (allyl alcohol) A pungentsmelling colourless unsaturated liquid alcohol, CH 2 =CHCH 2 OH; b.p.
97°C. It is found in wood alcohol and
can be prepared in the laboratory by
reducing propenal or by heating glycerol with oxalic acid. Industrially, it
is made by the high-temperature catalytic reaction between propenal and
2-propanol or by the hydrolysis of 2chloropropene, which is made by
chlorinating propene. Potassium permanganate oxidizes propenol to glycerol and silver oxide converts it to a
mixture of propenoic acid and propenal.
propenonitrile (acrylonitrile; vinyl
cyanide) A colourless liquid,
H 2 C:CHCN; r.d. 0.81; m.p. –83.5°C. It
is an unsaturated nitrile, made from
propanedioic acid
440
p
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gas for fuel.
propanedioic acid (malonic acid)
A white crystalline dicarboxylic acid,
HOOCCH 2 COOH; m.p. 132°C. It decomposes above its melting point to
ethanoic acid. Propanedioic acid is
used in the synthesis of other dicarboxylic acids.
propanoic acid (propionic acid) A
colourless liquid *carboxylic acid,
CH 3 CH 2 COOH; r.d. 0.99; m.p.
–20.8°C; b.p. 141°C. It is used to
make calcium propanate – an additive in bread.
propanol Either of two *alcohols
with the formula C 3 H 7 OH. Propan-1ol is CH 3 CH 2 CH 2 OH and propan-2-ol
is CH 3 CH(OH)CH 3 . Both are colourless volatile liquids. Propan-2-ol is
used in making propanone (acetone).
propanone (acetone) A colourless
Ûammable volatile compound,
CH 3 COCH 3 ; r.d. 0.79; m.p. –95.4°C;
b.p. 56.2°C. The simplest *ketone,
propanone is miscible with water. It
is made by oxidation of propan-2-ol
(see propanol) or is obtained as a byproduct in the manufacture of phenol from cumene; it is used as a
solvent and as a raw material for
making plastics.
propellant 1. A substance that
burns rapidly in a controlled way,
used to propel a projectile (e.g. from
a gun). In Ürearms, gunpowder and
cordite are common examples. 2. A
fuel used in a rocket engine. Usually
the propellant is a fuel and an oxidizer; for example kerosene or liquid
hydrogen with a liquid oxygen propellant. 3. A substance used to produce the spray in an aerosol can.
Aerosol propellants are volatile substances that can be liqueÜed under
pressure and are able to dissolve the
working substance. When the pressure is released, the liquid vaporizes
producing the spray. Formerly
chloroÛuorocarbons were used but
their use has been discontinued because of their effect on the ozone
layer. Most aerosol cans use liquid
hydrocarbon mixtures as the propellant.
propenal (acrolein) A colourless
pungent liquid unsaturated aldehyde,
CH 2 :CHCHO; r.d. 0.84; m.p. –87°C;
b.p. 53°C. It is made from propene
and is used in producing polyester
and polyurethane resins.
propene (propylene) A colourless
gaseous hydrocarbon, CH 3 CH:CH 2 ;
m.p. –185.25°C; b.p. –47.4°C. It is an
*alkene obtained from petroleum by
cracking alkanes. Its main use is in
the manufacture of polypropene.
propenoate (acrylate) A salt or
ester of *propenoic acid.
propenoic acid (acrylic acid) An
unsaturated liquid *carboxylic acid,
CH 2 :CHCOOH; m.p. 13°C; b.p.
141.6°C. It readily polymerizes and it
is used in the manufacture of
*acrylic resins.
propenol (allyl alcohol) A pungentsmelling colourless unsaturated liquid alcohol, CH 2 =CHCH 2 OH; b.p.
97°C. It is found in wood alcohol and
can be prepared in the laboratory by
reducing propenal or by heating glycerol with oxalic acid. Industrially, it
is made by the high-temperature catalytic reaction between propenal and
2-propanol or by the hydrolysis of 2chloropropene, which is made by
chlorinating propene. Potassium permanganate oxidizes propenol to glycerol and silver oxide converts it to a
mixture of propenoic acid and propenal.
propenonitrile (acrylonitrile; vinyl
cyanide) A colourless liquid,
H 2 C:CHCN; r.d. 0.81; m.p. –83.5°C. It
is an unsaturated nitrile, made from
propanedioic acid
440
p
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