how you could separate the components of a mixture of PbCL and NaSO and recover the two substances

Answer 1

recovering a significantly larger amount of SiO than was present in the original sample

Answer 2

Is all of that part of the same question or parts of incomplete questions?
There is neither a PbCl nor a NaSO. However, PbCl2 is not soluble in water while Na2SO4 is.