Question

what are the uses of mohr salt in daily life?

Answer 1

Ammonium iron(II) sulfate, or Mohr's salt, is the inorganic compound with the formula (NH)Fe(SO)·6HO. Containing two different cations, Fe2+ and NH+ , it is classified as a double salt of ferrous sulfate and ammonium sulfate. It is a common laboratory reagent because it is readily crystallized, and crystals resist oxidation by air. Like the other ferrous sulfate salts, ferrous ammonium sulfate dissolves in water to give the aquo complex [Fe(HO)]2+ , which has octahedral molecular geometry.[1]

Structure

This compound is a member of a group of double sulfates called Schönites or Tutton's salts. Tutton's salts form monoclinic crystals and have formula MN(SO). 6HO (M = various monocations). With regards to the bonding, crystals consist of octahedra [Fe(OH)]2+ centers, which are hydrogen bonded to sulfate and ammonium.[2]

Mohr's salt is named after the German chemist Karl Friedrich Mohr, who made many important advances in the methodology of titration in the 19th century.

Applications

In analytical chemistry, this salt is the preferred source of ferrous ions as the solid has a long shelf life, being resistant to oxidation. This stability extends somewhat to solutions reflecting the effect of pH on the ferrous/ferric redox couple. This oxidation occurs more readily at high pH. The ammonium ions make solutions of Mohr's salt slightly acidic, which slows this oxidation process.[1] [3] Sulfuric acid is commonly added to solutions to reduce oxidation to ferric iron.

It is used in the Fricke's dosemeter to measure high doses of gamma rays.[4]

Preparation

Mohr's salt is prepared by dissolving an equimolar mixture of hydrated ferrous sulfate and ammonium sulfate in water containing a little sulfuric acid, and then subjecting the resulting solution to crystallization. Ferrous ammonium sulfate forms light green crystals.

Contaminants

Common impurities include Mg, Mn, Ni, Pb, and Zn, many of which form isomorphous salts.[5]

References

Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.

Ephraim, Fritz (1926). Inorganic Chemistry. tr P. C. L. Thorne. London: Gurney and Jackson. pp. 484–485.

"Ammonium Ferrous Sulphate 100 g (Mohr's Salt)". 2012. Retrieved 13 June 2013.

Hickman, C.; Lorrain, S.; Barthe, J.R.; Portal, G. (1986). "Use of Mohr's Salt for High Level Gamma Dosimetry (Up to 108 Gy)". Radiatiation Protection Dosimetry. Oxford Journals. 17 (1-4): 255–257.

Vogel, Arthur I. (1961). A Text-book of Quantitative Inorganic Analysis Including Elementary Instrumental Analysis (3 ed.). Longmans. pp. 281–282.

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Mohr

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Look up mohr in Wiktionary, the free dictionary. Mohr may refer to: Mohr (surname), a German-language surname (also listing people with that surname) Mohr, Fars, a city in Iran Mohr County, an administrative subdivision...  More...

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Cerimetry

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Cerimetry or cerimetric titration, also known as cerate oximetry, is a method of volumetric chemical analysis developed by Ion Atanasiu. It is a redox titration in which a Fe -1,10-phenanthroline complex (ferroin) color change...  More...

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Double salt

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Double salts are salts containing more than one cation or anion, and are obtained by combination of two different salts which were crystallized in the same regular ionic lattice. Examples of double salts .

Answer 2

The Ammonium ferrous sulphate is also called the Mohr’s salt. It is widely used in the various fields in our daily life. Some of the main uses of Mohr’s salt are:

1. In Printing

2. For Titration purpose

3. To slow down the process of oxidation

4. In medicine

5. In electroplating