4-hydroxybutanoic acid lactone
(γ-butyrolactone) A colourless liquid
*lactone, C 4 H 6 O 2 ; b.p. 206°C. It is
used as a solvent and in the production of certain synthetic resins.
hydroxycerussite See lead(ii) carbonate hydroxide.
hydroxyethanoic acid See glycolic acid.
hydroxylamine A colourless solid,
NH 2 OH, m.p. 33°C. It explodes on
heating and may be employed as an
oxidizing agent or reducing agent. It
is made by the reduction of nitrates
or nitrites, and is used in making
nylon. With aldehydes and ketones it
forms *oximes.
A
• Information about IUPAC nomenclature
hydroxylation The introduction of
a hydroxyl group (–OH) into an organic compound. For example,
alkenes can be hydroxylated using
potassium permanganate or lead
ethanoate to give alcohols. In biochemistry, various enzymes can
bring about hydroxylation.
hydroxyl group The group –OH in
a chemical compound.
2-hydroxypropanoic acid See lactic acid.
hygroscopic Describing a substance that can take up water from
the atmosphere. See also deliquescence.
hyperconjugation The interaction
of sigma bonds with pi bonds in a
molecule, as in the interaction of a
methyl group with the benzene ring
in toluene. It is postulated to account
for the stability of some carbonium
ions. Hyperconjugation is often
thought of as a contribution of resonance structures in which a sigma
bond is broken to give ions; e.g.
C 6 H 5 CH 2
– H
+ in toluene. It has been
called no-bond resonance.
hyperÜne structure See fine
structure.
hypertonic solution A solution
that has a higher osmotic pressure
than some other solution. Compare
hypotonic solution.
hypochlorite See chlorates.
hypochlorous acid See chloric(i)
acid.
hypophosphorus acid See phosphinic acid.
hyposulphite See sulphinate.
hyposulphurous acid See sulphinic acid.
hypothesis See laws, theories,
and hypotheses.
hypotonic solution A solution
that has a lower osmotic pressure
than some other solution. Compare
hypertonic solution.
hypsochromic shift A shift of a
spectral band to shorter wavelengths
as a result of substitution in a molecule or as a result of a change in
the physical conditions. Compare
bathochromic shift.
4-hydroxybutanoic acid lactone
280
h
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(γ-butyrolactone) A colourless liquid
*lactone, C 4 H 6 O 2 ; b.p. 206°C. It is
used as a solvent and in the production of certain synthetic resins.
hydroxycerussite See lead(ii) carbonate hydroxide.
hydroxyethanoic acid See glycolic acid.
hydroxylamine A colourless solid,
NH 2 OH, m.p. 33°C. It explodes on
heating and may be employed as an
oxidizing agent or reducing agent. It
is made by the reduction of nitrates
or nitrites, and is used in making
nylon. With aldehydes and ketones it
forms *oximes.
A
• Information about IUPAC nomenclature
hydroxylation The introduction of
a hydroxyl group (–OH) into an organic compound. For example,
alkenes can be hydroxylated using
potassium permanganate or lead
ethanoate to give alcohols. In biochemistry, various enzymes can
bring about hydroxylation.
hydroxyl group The group –OH in
a chemical compound.
2-hydroxypropanoic acid See lactic acid.
hygroscopic Describing a substance that can take up water from
the atmosphere. See also deliquescence.
hyperconjugation The interaction
of sigma bonds with pi bonds in a
molecule, as in the interaction of a
methyl group with the benzene ring
in toluene. It is postulated to account
for the stability of some carbonium
ions. Hyperconjugation is often
thought of as a contribution of resonance structures in which a sigma
bond is broken to give ions; e.g.
C 6 H 5 CH 2
– H
+ in toluene. It has been
called no-bond resonance.
hyperÜne structure See fine
structure.
hypertonic solution A solution
that has a higher osmotic pressure
than some other solution. Compare
hypotonic solution.
hypochlorite See chlorates.
hypochlorous acid See chloric(i)
acid.
hypophosphorus acid See phosphinic acid.
hyposulphite See sulphinate.
hyposulphurous acid See sulphinic acid.
hypothesis See laws, theories,
and hypotheses.
hypotonic solution A solution
that has a lower osmotic pressure
than some other solution. Compare
hypertonic solution.
hypsochromic shift A shift of a
spectral band to shorter wavelengths
as a result of substitution in a molecule or as a result of a change in
the physical conditions. Compare
bathochromic shift.
4-hydroxybutanoic acid lactone
280
h
www.AzShimi.ir www.AzShimi.com