deg. C. |
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| |
| C_{6}H_{4}(CH_{3})NO_{2} Ortho-, meta-, and para- nitro-toluenes. |
| B.P. 218 deg., 230 deg., and 234 deg. C, Para compound solid. |
|____________________________________________________________________|
| |
| C_{6}H_{3}(CH_{3})_{2}NO_{2} Nitro-xylene. Liquid. |
|____________________________________________________________________|
| |
| C_{6}H_{2}(CH_{3})_{3}NO_{2} Nitro-mesitylene. Solid. |
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| |
| C_{6}H_{3}(CH_{3})(NO_{2})_{2} Di-nitro-toluenes. |
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| |
| C_{6}H_{4}Cl(NO_{2}) Nitro-chloro-benzenes. |
| |
| C_{6}Br_{4}(NO_{2})_{2} Tetra-bromo-di-nitrobenzene. |
|____________________________________________________________________|

The nitro compounds are mostly pale yellow liquids, which distil
unchanged, and volatilise with water vapour, or colourless or pale yellow
needles or prisms. Some of them, however, are of an intense yellow colour.
Many of them explode upon being heated. They are heavier than water, and
insoluble in it, but mostly soluble in alcohol, ether, and glacial acetic
acid.

Nitro-benzene, C_{6}H_{5}(NO_{2}), was discovered in 1834 by Mitscherlich.
It is a yellow liquid, with a melting point of +3 deg. C. It has an intense
odour of bitter almonds. It solidifies in the cold. In di-nitro-benzene,
the two nitro groups may be in the meta, ortho, or para position, the meta
position being the most general (see fig., page 4). By recrystallising
from alcohol, pure meta-di-nitro-benzene may be obtained in long
colourless needles. The ortho compound crystallises in tables, and the
para in needles. They are both colourless. When toluene is nitrated, the
para and ortho are chiefly formed, and a very little of the meta compound.

~Nitro Compounds of Benzene and Toluene.~--The preparation of th