Which colour precipitate is obtained when a solution of `Ca^(2+)` ions reacts with potassium ferrocyanide.

Explanation

To determine the color of the precipitate formed when a solution of \( \text{Ca}^{2+} \) ions reacts with potassium ferrocyanide, we can follow these steps:

### Step 1: Identify the reactants
The reactants in this reaction are calcium ions \( \text{Ca}^{2+} \) and potassium ferrocyanide \( \text{K}_4[\text{Fe(CN)}_6] \).

### Step 2: Write the reaction
When \( \text{Ca}^{2+} \) reacts with potassium ferrocyanide, the calcium ions will combine with the ferrocyanide ions \( [\text{Fe(CN)}_6]^{4-} \) to form a precipitate. The balanced reaction can be represented as:
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