Question

Give reason why
Fe +2 salts can be distinguish From Fe+3
salts by
OH solution
using
N Ha​

Answer 1

Answer:

Iron makes up about 5% by weight of the earth’s crust and is invariably present in all soils (see Table 11.1). The greatest part of soil Fe usually occurs in the crystal lattices of numerous minerals. The primary minerals in which Fe is present include the ferromagnesian silicates such as olivine, augite, hornblende and biotite. In biotite and illite Fe is located in the centre of the octahedra and may be di-or trivalent (Fanning et al. 1989). By weathering of these minerals Fe oxides such as goethite, haematite, and ferrihydrate are formed. The solubility of these FeIII oxides is extremely low (Schwertmann 1991). Goethite (α-FeOOH) is the most widespread Fe mineral in soils. Together with other Fe oxides it greatly influences soil colour which is between yellowish brown and brown (Allen and Hajek 1989). Haematite (α-Fe2O3) is also a widespread Fe oxide in soils particularly in well-drained tropical soils. In Oxisols and Ultisols it represents a signifcant proportion of the clay fraction. Ferrihydrate (HFe5O8·4H2O) has a high specific surface and for this reason may be of importance as an Fe source for plants. As a consequence of their high stability Fe oxides accumulate during oxidative weathering as hydrous oxides in the clay fraction. Thus in soils at an advanced stage of oxidative weathering as is the case of lateritic soils, these oxides together with Al oxides and kaolinite predominate in the profile. According to (1982) the solubility of Fe oxides/hydroxides decreases in the following sequence: Fe(OH)3 amorphous > Fe(OH)3 in soils > γ-Fe203 maghaemite > γ-FeOOH lepidocrocite > α-Fe2O3 haematite > α-FeOOH goethite.

Answer 2

Answer:

Iron makes up about 5% by weight of the

earth's crust and is invariably present in

all soils (see Table 11.1). The greatest part

of soil Fe usually occurs in the crystal

lattices of numerous minerals. The

primary minerals in which Fe is present

include the ferromagnesian silicates

such as olivine, augite, hornblende and

biotite. In biotite and illite Fe is located

in the centre of the octahedra and may

be di-or trivalent (Fanning et al. 1989).

By weathering of these minerals Fe

oxides such as goethite, haematite, and

ferrihydrate are formed. The solubility

of these Felll oxides is extremely low

(Schwertmann 1991). Goethite (a-FeOOH)

is the most widespread Fe mineral in

soils. Together with other Fe oxides it

greatly influences soil colour which is

between yellowish brown and brown

(Allen and Hajek 1989). Haematite

(a-Fe203) is also a widespread Fe

oxide in soils particularly in well-drained

tropical soils. In Oxisols and Ultisols

it represents a signifcant proportion

of the clay fraction. Ferrihydrate

(HFe508.4H20) has a high specific

surface and for this reason may be of

importance as an Fe source for plants.

How it helps you

Mark as brainliest ♥️

Follow me