For each of the following pairs of ions, determine whether a precipitate forms when solutions containing these ions are mixed and write the formulas...

1.    For each of the following pairs of ions, determine whether a precipitate forms when solutions containing these ions are mixed and write the formulas of any precipitates that form. Indicate the color of any precipitate that form.

a.    Na+ and I-

b.    Ba2+ and SO42-

c.    Pb2+ and NO3-

d.    Ag+ and S2-