Why won't I get iron(ll) nitrate if I mix iron (ll) chloride and silver nitrate?

Question

Does it have something to do with reactivity series?

Answer 1

You have:

Ag(+) + e -> Ag E0=+0.7995 V
Fe(+3) + e -> Fe(+2) E0=+0.771 V

So the reaction

Ag(+) + Fe(+2) -> Fe(+3) + Ag
Has E=0.7995-0.771=0.0285 >0 which means that the reaction will take place spontaneously.

So you could have quite a lot of Fe(III) nitrate forming and also having a mixed salt of nitrate and chloride, since metal Ag will leave the solution and Cl- will co-crystallize with Fe(+3) and NO3(-).

On the other hand the E is not that great and the Ag+ will be removed very well since AgCl has extremely low solubility...

So probably you will get Fe(NO3)2 but probably as a mixture with Fe(NO3)3; I don't know at what ratio.
Fe+2 in solution oxidates with time to Fe+3 by atmospheric O2 anyway, so you might want to find a better way to get Fe(NO3)2
Have a look at http://www.1911encyclopedia.org/Iron

Answer 2

You want to prepare a pure dry sample of iron (II) nitrate, a soluble salt. You mix iron (II) chloride (soluble) with silver nitrate (soluble), causing silver chloride (insoluble) to precipitate out. You filter that and crystallise the remaining solution of iron (II) nitrate and water to obtain iron (II) nitrate (crystals).


However u may note that the salts can not be mixed together . Their aqueous solutions have to mixed and heated for some time(both iron and silver are less reactive) to form the mentioned compounds. U may also take some other ferrous compounds ,like FeSO4.

Answer 3

silver and chloride wont be replaced, one more active than the other