Additional Homework Problems

CDP4-BB

For silicon to be used in the manufacture of microelectronic devices, it must contain less than 150 parts per trillion of impurities. This ultrapure silicon can be produced by reacting metallurgical silicon (98% pure) and HCl to form trichlorosilane and other products. This mixture is distilled and then the trichlorosilane is reacted with hydrogen at 1100 C to form polycrystalline silicon, HCl, and other silane products in the following reaction:

Set up a stoichiometric table for the following case:

x = 1

y = 2

z = 2

The total pressure may be taken to be 2 atm and the feed is stoichiometric. Sketch the concentrations of each species as a function of conversion.

Solution