What would be the products in these double displacement reactions?

Question

NaCl + KNO3

NH4OH + H2SO4

CuSO4 + Zn(NO3)2

CuSO4 + NH4Cl

FeCl3 + NH4OH

And how can I pre-determine if there is goin to be a reaction in the first place?

Answer 1

NaCl + KNO3 --------------> NaCl + KNO3,
Potassium is more reactive than sodium so nothing happens

2NH4OH + H2SO4-------------> (NH4)2SO4 + 2H2O

CuSO4 + Zn(NO3)2------------> Cu(NO3)2 + ZnSO4

CuSO4 + 2NH4Cl-----------------> CuCl2 + (NH4)2SO4

FeCl3 + 3NH4OH-------------------> Fe(OH)3 + 3NH4Cl

To determine if a reaction takes place look at the chemical reactivity series of the metals.

Answer 2

There will only be a reaction if one of the new combinations of anions and cations forms a precipitate, or if you have protons and hydroxide ions that will form water (an acid + a base).

So, in the first one, nothing will happen because all of the ions will remain in solution.

In the second, you have an acid (H2SO4) and a base (NH4OH). So, they'll react to form water.

So, you need to determine for the rest whether a precipitate will form or something like that. You should have a set of solubility rules that will help you determine what might precipitate.

Hope this helps.

Answer 3

NaCl + KNO3 -> No reaction

2NH4OH + H2SO4 -> (NH4)2SO4 + 2H2O

CuSO4 + Zn(NO3)2 -> ZnSO4 + Cu(NO3)2

CuSO4 + 2NH4Cl -> CuCl2 + (NH4)2SO4

FeCl3 + 3NH4OH -> Fe(OH)3 + 3NH4Cl

If one of the products has a lower solubility product and can therefore precipitate out, reaction will occur.