Mixtures of SiC14 and PhBr in a mole ratio of 1/1 underwent reversible exchange, which approached equilibrium at 310 OC in about 115 h. A constant value of about 0.07 was approached when the GLC area ratio of PhCl/PhBr was multiplied by the ratio of the Si-Br bonds/Si-C1 bonds. This latter ratio was calculated as the sum of the area percents of individual halosilanes multiplied by the number of Br or C1 atoms in each halosilane. ...