Chemistry Can any acid only oxidize Fe to 2 valence?

No. Both concentrated sulphuric acid and nitric acid oxidize iron to +3 valence. This is because, in concentrated sulfuric acid, the real reduction reaction is +6 s, not +1 h; Similarly, in concentrated nitric acid, it is +5 n that reacts with iron, not +1 h

The specific equation is a bit troublesome because of the trim, so I won't write it out here.

However, the premise here is that there must be an excess of acid. If there is an excess of Fe, the excess Fe will react with Fe3+ to form Fe2+.

It is wrong for any acid to oxidize Fe only to +2 valence. Fe reacts with concentrated HNO3 to form Fe(No)3, and Fe reacts with Fe(No)3 to form Fe(No3)2 when Fe is excessive.

No, you have to know the essence of the reaction between iron and concentrated acid, concentrated sulfuric acid and nitric acid will passivate iron into trivalent iron oxide and then exhibit its acidic and basic iron oxide reaction. If divalent iron ions are generated, it means that the ferric ions in the iron excess solution are 2Fe3 + Fe = 3Fe2+

The oxidation of the acid comes from the ionization of H+ and acid groups with the acid. Some acids have no oxidizing properties, and this acid is called non-oxidizing acid, such as hydrochloric acid and dilute sulfuric acid.

The valence state to which Fe is oxidized depends on the strength of the oxidation of the acid. H+ can only oxidize Fe to Fe2+, and the acid groups in concentrated sulfuric acid can only oxidize Fe to Fe2+. However, the acid group in nitric acid oxidizes Fe to Fe 3+, and Fe 2+ can only be obtained when Fe is excessive, which is also generated by the reduction of Fe 3+ obtained by the oxidation of nitric acid by excess Fe.

Iron reacts with a weak oxidant to give +2, reacts with a strong oxidant to get +3, +3 iron has strong oxidizing properties, and +2 iron has weak reducing properties.

Common oxidation of iron to bivalent are: iodine, sulfur element, Fe3+, Cu2+, H+, etc.

The common ones that can oxidize iron to bivalent are: electrode potential greater than Fe3+ Fe, such as fluorine, oxygen, chlorine, bromine, concentrated sulfuric acid Hno3, Kmno4, etc.

Note: 1. Iron is burned in oxygen, and iron tetroxide is formed by reacting with water vapor at high temperatures. 2. After hydrogen peroxide oxidizes ferric iron to ferric iron, ferric iron catalyzes the decomposition of hydrogen peroxide to generate ferric iron? The reaction formula is as follows:

2fe2+ +h2o2 +2h+=2fe3+ +2h2o
fe3+ +h2o2=2fe2+ +2h+ +o2

Iron reacts with a weak oxidant to get +2, and reacts with a strong oxidant to get +3, when +3 iron has strong oxidation, +2 is weakly reduced.

Because the reaction between dilute hydrochloric acid and iron bai reflects the acidity of dilute hydrochloric acid. Acidity can only cause the metal to generate low-valence ionic DAO. If it is encountered, strong oxygen formatted acid (sulfur weight.

acids or nitric acids) will oxidize to trivalent. It can be understood in this way: the hydrogen ions in dilute hydrochloric acid have poor oxidation and can only oxidize iron to bivalent.

The oxidation of iron ions is greater than that of copper ions, and iron elements can reduce copper ions, which can naturally reduce iron ions. Reducibility from large to small: k, ca, na, mg, al, zn, fe, sn, pb, h, cu, hg, ag, pt, au.

Ferrous ions are generally light green, have strong reducing properties, and can react with many oxidants, such as chlorine, oxygen, etc. Therefore, it is best to prepare the ferrous ion solution and add some iron powder to it during storage (iron ions have strong oxidation and can react with iron elements to form ferrous ions) Ferrous ions also have oxidation, but the oxidation is relatively weak, and can be replaced with magnesium, aluminum, zinc and other metals.

Test method for iron ions:

1) Add phenol to appear purple-red (complex).

2) Add SCN-(ion) to appear hemo-red (complex).

3) Sodium hydroxide has a reddish-brown precipitate, and the pH of the solution (at room temperature) from the beginning of the precipitation to the complete precipitation:

Because the reaction between dilute hydrochloric acid and iron reflects the acidity of dilute hydrochloric acid. Acidity can only cause the metal to produce valence ions. If it encounters a strong oxidizing acid (sulfuric acid or nitric acid), it will oxidize to trivalent.

We can understand it this way: the hydrogen ions in dilute hydrochloric acid have poor oxidation and can only oxidize iron to bivalent.

The oxidation of hydrogen ions is weak, and FE cannot be oxidized to ferric iron.

Valency indicates the number of electrons gained and lost by the atomic liquid when the atoms are combined with each other. Valency is also a property exhibited by an element in the formation of a carouson.

The valency is set to conveniently represent the number of atoms that are combined with each other.

Fe2+ means that the iron atom has lost two electrons, so its valency is specified as +2

Since the iron atom loses 2 electrons to form Fe2+ ions, the valency of Fe2+ is 2

Fe atom forms Fe2+ after losing 2 electrons, so the valency of Fe2+ in the compound is 2.

At room temperature, Fe will be blunted by concentrated nitrate, and a dense oxide film will be formed on the surface, preventing the reaction from continuing.

After heating, the oxide film is destroyed and Fe can react with concentrated nitric acid.

If there is an excess of concentrated nitric acid, Fe(No3)3 is generated, and if Fe is excessive, Fe(No3)2 is generated

Fe + 6Hno3 (concentrated) = Heating = Fe (No3) 3 + 3H2O + 3No2 (gas Nianhong).

Fe + 4Hno3 (concentrated) = Heating = Fe (No3) 2 + 2H2O + 2No2 (gas).

Dilute nitric acid will also react with Fe to obtain Fe(No3)3, and Fe(No3)2 if Fe is excessive

Fe + 4Hno3 (dilute) = Fe (No3) 3 + No (gas) + 2H2O

3Fe + 8Hno3 (dilute) = 3Fe (No3) 2 + 2No (gas) + 4H2O