Note 1 — Chapter XVIII · SILICON AND THE OTHER ELEMENTS OF THE FOURTH GROUP

Chloroform, CHCl3, boils at 60°, and silicon chloroform, SiHCl3, at 34°; silicon ethyl, Si(C2H5)4, boils at about 150°, and its corresponding carbon compound, C(C2H5)4, at about 120°; ethyl orthosilicate, Si(OC2H5)4, boils at 160°, and ethyl orthocarbonate, C(OC2H5)4, at 158°. The specific volumes in a liquid state—that is, those of the silicon compounds—generally are slightly greater than those of the carbon compounds; for example, the volumes of CCl4 = 94, SiCl4 = 112, CHCl3 = 81, SiHCl3 = 82, of C(OC2H5)4 = 186, and Si(OC2H5)4 = 201. The corresponding salts have also nearly equal specific volumes; for example, CaCO3 = 37, CaSiO3 = 41. It is impossible to compare SiO2 and CO2, because their physical states are so widely different.