Question

The green colour of 0.1 M F.A.S. solution turns to which colour if we keep that solution open
r for a long time?
a.red
b. blue
c. yellowish brown
d. violet​

Answer 1

Answer:

red

solution turns to which colour if we keep that solution open r for a long time

Answer 2

Ferrous Ammonium Sulphate Storage

Explanation:

• Ferrous Ammonium Sulphate is additionally called Mohr’s salt a light green color sand like crystalline solid.
• It's a hazardous substance and its preparation involves equimolar ratio of ammonium sulphate and hydrous ferrous sulphate with an considerable volume of acid.
• It is prepared by dissolving equimolar mixture of hydrated ferrous sulfate and ammonium sulfate in water containing a bit sulphuric acid. the answer is subjected to crystallization, ferrous ammonium sulfate separates out from the solution.
• The addition of sulphuric acid during this experiment prevents the hydrolysis of this salt. Ferrous ammonium sulfate could be a pale green crystalline compound which doesn't effloresce like ferrous sulfate. it's less readily oxidized than FeSO4 and thus, a higher volumetric reagent in preference to ferrous sulfate.
• Mohr’s salt is additionally called as double salt which contain more than one simple salt. It undergoes complete dissociation in aqueous solutions.
• Mohr’s salt is light green transparent octahedral crystals. it's soluble in water giving acidic solution which turns blue paper red and provides effervescence with sodium bicarbonate evolving carbon dioxide.

If the FAS solution is kept in air for an extended time, the iron oxidizes and results in a yellowish brown color.