Discussion:
Practice Exam - Boron Halides; Radius Ratio Rule; Monomer vs. Dimer; Viscosity; Zeolites
1. Explain why:
a. Lewis acid strengths of boron halides are in the order BBr3 >> BCl3 > BF3 opposite to the order expected based on electronegativities.
b. Radius ratio rule is correct only 66% of the times in predicting coordination numbers in ionic compounds.
c. Me3B is a monomer, whereas Me3Al exits as a dimer.
d. Viscosity of liquid sulfur increases sharply at ~ 159oC
e. Zeolites are used as shape selective reforming catalysts.