Note 47 bis — Chapter XI · THE HALOGENS: CHLORINE, BROMINE, IODINE, AND FLUORINE

See, for example the melting point of NaCl, NaBr, NaI in Chapter II. Note 27. According to F. Freyer and V. Meyer (1892), the following are the boiling points of some of the corresponding compounds of chlorine and bromine:

BCl₃ 17° BBr₃ 90°

SiCl₃ 59° SiBr₄ 153°

PCl₃ 76° PBr₃ 175°

SbCl₃ 223° SbBr₃ 275°

BiCl₃ 447° BiBr₃ 453°

SnCl₄ 606° SnBr₄ 619°

ZnCl₂ 730° ZnBr₂ 650°

Thus for all the more volatile compounds the replacement of chlorine by bromine raises the boiling point, but in the ease of ZnX₂ it lowers it (Chapter XV. Note 19).