NITROGEN TETROXIDE (NO2 or N2O4).
111. Preparation.
Experiment 70.—Lift from the water-pan a receiver of NO, and note the colored fumes. They are NO2, or N2O4, nitrogen tetroxide. NO + O = NO2. Is NO combustible? What is the source of O in the experiment?OXIDES OF NITROGEN.
NITROGEN TRIOXIDE (N2O3).
112. Preparation.
Experiment 71.—Put into a t.t. 1 g. of starch and 1 cc. of HNO3.
Heat the mixture for a minute. The red fumes are N2O3 and NO2.
Nitrogen pentoxide, N2O5, is an unimportant solid. United with water it forms HNO3. N2O5 + H2O = 2HNO3.
CHAPTER XXIII.
LAWS OF DEFINITE AND OF MULTIPLE PROPORTION.
113. Weight and Volume.—We have seen that water contains two parts of H by volume to one part of O; or, by weight, two parts of H to sixteen of O. These proportions are invariable, or no symbol for water would be possible. Every compound in the same way has an unvarying proportion of elements.