Dictionary of Chemistry [6th Ed.]

227 °C. It is made by the chlorination

of benzene with an iron(III) chloride

catalyst or by treating hexachlorocy-

clohexane with chlorine in hexa-

chloroethane. It is used to preserve

wood and dress seeds, and in the

manufacture of hexaÛuorobenzene.

hexacyanoferrate(II)(ferro-

cyanide)A complex iron-containing

anion, [Fe(CN 6 )]4–, used as a solution

of its potassium salt as a test for fer-

ric iron (iron(III)), with which it

forms a dark blue precipitate of

Prussian blue. The sodium salt is

used as an anticaking agent in com-

mon salt.

hexacyanoferrate(III)(ferri-

cyanide)A complex iron-containing

anion, [Fe(CN) 6 )]3–, used as a solution

of its potassium salt as a test for fer-

rous iron (iron(II)), with which it

forms a dark blue precipitate of

Prussian blue.

hexadecane(cetane)A colourless

liquid straight-chain alkane hydrocar-

bon, C 16 H 34 , used in standardizing

*cetane numbers of Diesel fuel.

hexadecanoateSee palmitate.

hexadecanoic acidSee palmitic

acid.

hexagonal close packingSee

close packing.

hexagonal crystalSee crystal sys-

tem.

hexahydrateA crystalline com-

pound that has six moles of water

per mole of compound.

hexamethylenetetramineSee

hexamine.

hexamine(hexamethylenete-

tramine)A white crystalline com-

pound, C 6 H 12 N 4 , made by the

condensation of methanal with am-

monia. It has been used as a solid

fuel for camping stoves and as an an-

tiseptic for treating urinary infec-

tions in medicine. It is used in the

production of *cyclonite.

hexacyanoferrate(II) 270

h

N

N

N

N

Hexamine

hexanedioate(adipate)A salt or

ester of hexanedioic acid.

hexanedioic acid (adipic acid)A

carboxylic acid, (CH 2 ) 4 (COOH) 2 ; r.d.

1.36; m.p. 153°C; b.p. 265°C (100

mmHg). It is used in the manufacture

of *nylon 6,6. See also polymeriza-

tion.

6-hexanelactamSee caprolactam.

hexanitrohexaazaisowurtzitane

See hniw.

hexanoate(caproate) A salt or

ester of hexanoic acid.

hexanoic acid (caproic acid) A liq-

uid fatty acid, CH 3 (CH 2 ) 4 COOH; r.d.

0.93; m.p. –3.4°C; b.p. 205°C. Glyc-

erides of the acid occur naturally in

cow and goat milk and in some veg-

etable oils.

hexoseA *monosaccharide that

has six carbon atoms in its mol-

ecules.

hexyl group (hexyl radical)The

organic group CH 3 CH 2 CH 2 CH 2 -

CH 2 CH 2 –, derived from hexane.

HFC(hydroÛuorocarbon) See halo-

carbons.

highest occupied molecular or-

bital(HOMO)The orbital in a mol-

ecule that has the highest energy

level occupied at the temperature of

absolute zero. The highest occupied

molecular orbital and the lowest un-

occupied molecular orbital (LUMO)