A salt may be prepared by the reaction of 1 salt w/ another salt, if 1 of the products is insoluble...?

Question

WHICH ONE OF THE FOLLOWING REACTIONS IS THIS DEMONSTRATED?

A. 3 Sr(NOsub3)sub 2 + 2 Ksub3POsub4 --> Srsub3(POsub4)sub2 + 6 KNOsub3

B. CuClsub2 + NHsub4NOsub3 ---> Cu(NOsub3)sub2 + 2NHsub4Cl

C. BaClsub2 + 2 NaNOsub3 ---> Ba(NOsub3)sub2 + 2 NaCl

D.(NHsub4)sub2COsub3 + Ksub2SOsub4 + Ksub2COsub3

E. NaNOsub3 + KCl --> NaCl + KNOsub3

I don't get this some please help. You may have to write this out on a piece of paper the proper way. I don't understand this!

Answer 1

A is the correct answer.

Basically, you are being asked which of the reactions will form an insoluble precipitate. Almost every chemistry book will have a set of rules that you can use to determine whether a salt will be soluble or insoluble. One book I know basically says that if a salt is formed of +2 or +3 charged metal ions and -2, or -3 charged anions, then it will most likely be insoluble. That is certainly the case for the Sr product in your first equation.