A: `FeCl_(3)`, reacts with KCNS to give blood red colour.
R: `FeCl_(3)`, reacts with KCNS to form potassium ferro-ferricyanide

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To solve the question regarding the assertion and reason provided, we will analyze both statements step by step.

### Step 1: Analyze the Assertion
The assertion states that `FeCl3` reacts with `KCNS` to give a blood red color.

- **Reaction**: When `FeCl3` (ferric chloride) reacts with `KCNS` (potassium thiocyanate), the reaction can be represented as:
\[ \text{FeCl}_3 + 3 \text{KCNS} \rightarrow \text{Fe(SCN)}^{2+} + 3 \text{KCl} \]
- **Complex Formation**: The product formed is `Fe(SCN)^{2+}`, which is known as ferric thiocyanate.
- **Color**: This complex is known to have a blood red color.

### Step 2: Analyze the Reason
The reason states that `FeCl3` reacts with `KCNS` to form potassium ferro-ferricyanide.

- **Incorrect Reaction**: The term "potassium ferro-ferricyanide" refers to a different complex that involves cyanide ions (CN^-), not thiocyanate ions (SCN^-).
- **Clarification**: The correct product formed from the reaction of `FeCl3` with `KCNS` is `Fe(SCN)^{2+}`, not any cyanide complex.

### Conclusion
- **Assertion**: True. The reaction of `FeCl3` with `KCNS` does indeed produce a blood red colored complex (ferric thiocyanate).
- **Reason**: False. The reason provided is incorrect as it mentions the formation of a different complex involving cyanide instead of thiocyanate.

### Final Answer
The assertion is true, but the reason is false.

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