a. Chem. and Electr. [f. CHLOR-INE + -OUS; cf. F. chloreux.]
1. Abounding in chlorine; spec. containing chlorine in greater proportion relatively to oxygen than chloric compounds, as in chlorous oxide or anhydride, Cl2 O3, a yellowish green gas; chlorous acid (hydrogen chlorite), H Cl O2, the salts of which are chlorites.
The compounds with a still greater proportion of chlorine are hypochlorous oxide or anhydride (Cl2O), a pale reddish yellow gas; and hypochlorous acid (H Cl O), the salts of which are hypochlorites.
1845. G. Day, trans. Simon’s Anim. Chem., I. 41. Replaced by six atoms of chlorous acid.
1873. Watts, Fownes’ Chem., 184. Hypochlorous and chlorous acids … by direct oxidation of hydrochloric acid. Ibid., 186. Chlorous Oxide.
2. Of the quality of chlorine: applied to elements or radicals that unite with hydrogen to form an acid, and are relatively electro-negative. Chlorous pole, the negative pole of a galvanic battery, which exhibits the same attraction as a chlorous element.
1881. Williamson, in Nature, XXIV. 414. Such primary compounds were classified … into electro-positive or basylous, and electro-negative or chlorous compounds. Ibid., 417. Illustrations of the greater atomic values which elements assume by combining with both chlorous and basylous atoms than with atoms of the one kind only.
