Freon-12 is used as a refrigerant in central home air conditioners. The rate of effusion of Freon-

Question:

Freon-12 is used as a refrigerant in central home air conditioners. The rate of effusion of Freon- 12 to Freon- 11 (molar mass = 137.4 g/ mol) is 1.07: 1. The formula of Freon-12 is one of the following: CF₄, CF₃Cl, CF₂Cl₂, CFCl₃, or CCl₄. Which formula is correct for Freon-12?