The ammonia complex of trimethylborane, (NH₃)B(CH₃)₃, dissociates at 100°C to its components with K_p = 4.62 (when the pressures are in atmospheres).

If NH₃ is changed to some other molecule, the equilibrium constant is different.
For [(CH₃)₃P]B(CH₃)₃ K_p = 0.128
For [(CH₃)₃N]B(CH₃)₃ K_p = 0.472

(a) If you begin an experiment by placing0.010 mol of each complex in a flask, which would have the largest partial pressure of B(CH₃)₃ at 100°C?

(b) If 0.73 g (0.010 mol) of (NH₃)B(CH₃)₃ is placed in a 1.25-L flask and heated to 100°C,what is the partial pressure of each gas in the
equilibrium mixture, and what is the total pressure? What is the percent dissociation of(NH₃)B(CH₃)₃?

Transcribed Image Text:

(NH3)B(CH3)3(g) N B(CH3)3(g) + NH3(g)