Ans. a. From the stoichiometry of equation 1
through 4-
2 moles of aluminum produce 2 moles of alum.
Thus, 3.4 x 10-2 moles of aluminum produce 3.4 x
10-2 moles of alum.
Molecular mass of alum = 474.39 gm/ mol
Theoretical yield of alum (g) = moles of alum x molecular mass
of alum
                                  Â
      =3.4 x 10-2 moles x
474.39 gm/ mol   Â
                                  Â
      = 16.13 gm
Ans. b. % yield = (yield obtained / theoretical
yield) x 100
                      Â
= (12.4 gm / 19.6 gm) x 100
                      Â
= 63.27 %
