Question

In the reaction: \(\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]+\mathrm{K}_{2} \mathrm{CO}_{3} \longrightarrow\) the product formed is (a) \(\mathrm{FeCO}_{3}\) (b) \(\mathrm{KCN}\) (c) \(\mathrm{KFeCO}_{3}\) (d) \(\mathrm{K}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{4}\right]\)

Short answer

The product formed is \(\mathrm{FeCO}_{3}\).

Step-by-step solution

Identify the Components

The reactants are potassium hexacyanoferrate(II), represented as \(K_4[Fe(CN)_6]\), and potassium carbonate, represented as \(K_2CO_3\).

Analyze Reactant Interactions

Potassium hexacyanoferrate(II) reacts with potassium carbonate. The complex ion \([Fe(CN)_6]^{4-}\) is not likely to undergo a simple displacement or decomposition in the presence of \(K_2CO_3\).

Predict Potential Products

Consider the stability and possible formation of products. Iron(II) carbonate, \(FeCO_3\), is a common precipitate when reacting metal carbonates and complexes of \(Fe^{2+}\). However, formation requires the decomposition of complex ions.

Check for Existing Literature and Common Reactions

In literature, there is no common mention of reactions leading to products (b), (c), or (d) specifically in the interaction between \(K_4[Fe(CN)_6]\) and \(K_2CO_3\). Considering common knowledge, \(FeCO_3\) is the most tangible product if the ion breaks to react with carbonate ions.

Conclude on the Most Likely Product

Based on common chemical knowledge and absence of specific reaction paths leading to options (b), (c), or (d), \(FeCO_3\) can precipitate out, making it the most likely product.

Key concepts

Potassium hexacyanoferrate(II)

Potassium hexacyanoferrate(II) is a chemical compound represented as \(K_4[Fe(CN)_6]\). It is a classic example of a coordination complex, where the central metal atom, iron in the +2 oxidation state, is surrounded by cyanide ions \((CN^-)\) as ligands. This complex is quite stable and is known for its deep blue color when it forms compounds such as Prussian blue in combination with ferric ions.Potassium hexacyanoferrate(II) finds its relevance both in industrial processes and analytical chemistry. It's used in the "blueprint" or cyanotype processes, where its ability to undergo further chemical reactions comes into play. More importantly, in the realm of coordination chemistry, it serves as a model compound to understand the formation, geometry, and reactivity of complex ions.Students should remember that the stability of the \([Fe(CN)_6]^{4-}\) complex largely controls its reactivity in chemical equations. This stability often prevents it from undergoing straightforward reactions such as simple displacements or decomposition without external agents like strong acids or oxidants.

Iron(II) carbonate

Iron(II) carbonate, commonly noted as \(FeCO_3\), is a pale green compound that can form a precipitate in certain reactions, particularly when iron(II) ions interact with carbonate ions in solution. The process of forming \(FeCO_3\) typically occurs when iron solutions mix with carbonates in environments where no complexing agents interfere significantly.The precipitation of \(FeCO_3\) becomes a significant consideration in various fields of inorganic chemistry. For students, understanding its formation helps in grasping concepts of reaction prediction and product stability. The occurrence of this reaction is often predicted by considering the solubility product (Ksp) of \(FeCO_3\). When the product of the iron(II) ion concentration and carbonate ion concentration exceeds the solubility product, precipitation occurs.In our exercise, the formation of \(FeCO_3\) from \(K_4[Fe(CN)_6]\) and \(K_2CO_3\) suggests that the complex ion \([Fe(CN)_6]^{4-}\) could potentially break down, allowing \(Fe^{2+}\) to interact with \(CO_3^{2-}\). This leads to the precipitation of iron(II) carbonate, showcasing a situation where the stability of a complex ion influences product prediction.

Complex ions reactions

Complex ion reactions revolve around the interactions and reactions that involve complex ions, like those found in coordination compounds. These reactions are detailed examples of chemical reactivity where ligands and central metal ions play pivotal roles in determining the overall outcome.Such reactions often include processes like ligand substitution, where existing ligands in a complex can be exchanged for others without disturbing the integrity of the metal and its oxidation state. These exchanges are typically governed by factors such as ligand strength, the central metal's oxidation state, and solution conditions.In our example involving \(K_4[Fe(CN)_6]\) and \(K_2CO_3\), we notice a lack of direct complex ion exchange, primarily due to the high stability of \([Fe(CN)_6]^{4-}\). However, the potential introduction of carbonate ions into the solution creates an opportunity for the less stable \(Fe^{2+}\) ions to react independently if released from the complex. Consequently, the understanding of coordination chemistry underpins the analysis of potential outcomes in reactions like these.Students exploring complex ions should note the delicate balance between stability and reactivity that dictates how these compounds behave in various chemical environments. This adds a rich, deeper layer to predicting products in coordination chemistry scenarios.