solubility of ionic compounds?

Question

Which of the following pairs of 0.1 M aqueous solutions would result in the formation of a precipitate upon mixing?
a) lead acetate + potassium hydroxide
b) ammonium acetate + cadmium nitrate
c) sodium chromate + nickel(II) iodide
d) strontium perchlorate + iron(II) sulfate

Which of the following pairs of 0.1 M aqueous solutions would result in the formation of a precipitate upon mixing?

a) lead acetate + potassium nitrate
b) sodium chromate + ammonium phosphate
c) nickel(II) nitrate + sodium sulfide
d) strontium perchlorate + iron(II) chloride

Answer 1

d) Strontium sulfate

c) Nickel (II) sulfide