A solution of $FeCl _3$ when treated with $K _{ t }\left[ Fe ( CN )_6\right]$ gives a prussiun blue precipitate due to the formation of
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The formation of Prussian blue is a qualitative test for the presence of ferric ions (Fe3+) in solution
- $Fe \left[ Fe ( CN )_6\right]$
- $K \left[ Fe _2( CN )_6\right]$
- $Fe _4\left[ Fe ( CN )_6\right]_3$
- $Fe _3\left[ Fe ( CN )_6\right]_2$
The Correct Option is C
Solution and Explanation
The Prussian blue precipitate is formed when ferric ions (\( \text{Fe}^{3+} \)) react with hexacyanoferrate (\( [\text{Fe(CN)}_6]^{4-} \)) ions. The product of this reaction is \( \text{Fe}_4[\text{Fe(CN)}_6]_3 \), which is an insoluble complex that imparts the characteristic deep blue color.
Step 1: Ferric chloride (\( \text{FeCl}_3 \)) dissociates to produce \( \text{Fe}^{3+} \) ions in solution.
Step 2: Potassium hexacyanoferrate (\( \text{K}_4[\text{Fe(CN)}_6] \)) dissociates to produce \( [\text{Fe(CN)}_6]^{4-} \) ions in solution.
Step 3: \( \text{Fe}^{3+} \) ions combine with \( [\text{Fe(CN)}_6]^{4-} \) to form the insoluble complex \( \text{Fe}_4[\text{Fe(CN)}_6]_3 \), known as Prussian blue.
\( 4\text{Fe}^{3+} + 3[\text{Fe(CN)}_6]^{4-} \rightarrow \text{Fe}_4[\text{Fe(CN)}_6]_3 \downarrow \) (Prussian blue precipitate)
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Concepts Used:
Solutions
A solution is a homogeneous mixture of two or more components in which the particle size is smaller than 1 nm.
For example, salt and sugar is a good illustration of a solution. A solution can be categorized into several components.
Types of Solutions:
The solutions can be classified into three types:
- Solid Solutions - In these solutions, the solvent is in a Solid-state.
- Liquid Solutions- In these solutions, the solvent is in a Liquid state.
- Gaseous Solutions - In these solutions, the solvent is in a Gaseous state.
On the basis of the amount of solute dissolved in a solvent, solutions are divided into the following types:
- Unsaturated Solution- A solution in which more solute can be dissolved without raising the temperature of the solution is known as an unsaturated solution.
- Saturated Solution- A solution in which no solute can be dissolved after reaching a certain amount of temperature is known as an unsaturated saturated solution.
- Supersaturated Solution- A solution that contains more solute than the maximum amount at a certain temperature is known as a supersaturated solution.