Question

Acrylonitrile, C3H3N, is an important industrial chemical. Propene, C3H6, reacts with ammonia & oxygen in the gas phase to produce acrylonitrile and water vapor according to the following balanced chemical equation. 150 g of propene was reacted with 270.0 L ammonia & excess oxygen (both STP). 175g of C3H3N was isolated after the reaction.

        C3H6(g) +       2NH3(g) +      3O2(g)    ->      2 C3H3N(l) +     6H2O(g)

MM: 42.080             17.0304      31.9988                  53.0634 1         8.0153

(a) Calculate the theoretical yield of acrylonitrile based on the amounts of reactants given.

(b) What is the actual yield of the acrylonitrile?

(c) Calculate the percent yield of acrylonitrile.

Answer 1

STP : n = P V / R T

              = 1 x 270 / 0.0821 x 273

             = 12.05

mass of NH3 = 12.05 x 17 = 205 g

C3H6(g)   +       2NH3(g) +      3O2(g)    ---------------->      2 C3H3N(l) +     6H2O(g)

42.08 g              34.0608 g                                               106.1268 g

150                   205 g

limiting reagent is C3H6

a) theoretical yield   = 106.1268 x 150 / 42.08

                                  = 378.3 g

b) actual yield = 175 g

c) percent yield = actual yield x 100 / theoretical yield

                           = 175 x 100 / 378.3

                            = 46.2 %