iron react witn acid

Oxidation number: iron < iron(II) < iron(III)
The hydrogen ions in acids can convert iron to iron(II) ions, but NOT iron(III) ions as hydrogen ions do NOT have sufficient oxdizing power to oxidize iron(II) to iron(III).
However, acids with oxidizing power (acting as oxidizing agent) can react with iron to give iron(III) ions.

Non-oxidizing acids, such as hydrochloric acid, dilute sulphuric acid, diluteethanoic acid and very dilute nitric acid, react with iron to give iron(II)ions.
Fe(s) + 2H^+(aq) → Fe^2+(aq) + H2(g)

Oxidizing acids (i.e. acids with oxidizing power), such as concentrated nitricacid, dilute nitric acid and concentrated sulphuric acid (usually when hot), reactswith iron to give iron(III) ions.

2011-08-27 17:21:42 補充：
The crystal lattice of iron(II)iron(III) oxide contains iron(II), iron(III) and oxide ions. When iron is burned in oxygen (or air), iron(II)iron(III) oxide is formed. This is mainly due to that the crystal lattice of iron(II)iron(III) oxide is stable.

2011-08-27 17:21:49 補充：
On the other hand, iron(II)iron(III) compounds cannot be formed in solution because the compounds in solution exist as mobile ions, but not crystal. Therefore, it is not necessary to consider the stability in solution.

Fe + 2HCl à FeCl2 + H2because iron of outermost shell electron have 2+
chlorine has 1- ,so need two chlorine ion can share with iron !

iron (II) chloride<----Ans!

impossible have (II)(III) !!!

there will be FeCl2 as 001 said
it can be shown by the colour of the solution turns to green....
however...
don't know the reason x2

Fe + 2HCl ----> FeCl2 + H2
So, iron(II) chloride will be produced.

But I don't know the reason.