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lodine crystals are added to liquor ammo...

lodine crystals are added to liquor ammonia and the brown precipitate so formed is separated , dried and spread on floor. On walking over the precipitate harmless explosion occurs releasing coloured gas. The ppt. and coloured gas are respectively

A

`NI_3,I_2`

B

`NH_4I and I_2`

C

`NH_3NI_3,I_2`

D

`NH_3NI_3,I_2O_5`

Text Solution

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To solve the question step by step, we will analyze the reaction between iodine crystals and liquid ammonia, identify the precipitate formed, and determine the colored gas released upon walking over the precipitate. ### Step 1: Identify the Reaction When iodine (I2) is added to liquid ammonia (NH3), a chemical reaction occurs. The balanced equation for this reaction is: \[ \text{NH}_3 + \text{I}_2 \rightarrow \text{NH}_4\text{I} \] ### Step 2: Determine the Precipitate The product formed in this reaction is ammonium iodide (NH4I). However, when excess iodine is present, the reaction can lead to the formation of a brown precipitate known as nitrogen triiodide (NI3): \[ 3 \text{NH}_3 + \text{I}_2 \rightarrow \text{NI}_3 + 3 \text{NH}_4\text{I} \] The brown precipitate that forms is nitrogen triiodide (NI3). ### Step 3: Analyze the Explosion and Colored Gas When the brown precipitate (NI3) is disturbed (for example, by walking over it), it can undergo a decomposition reaction, which is relatively harmless but can produce a small explosion. The decomposition of nitrogen triiodide produces nitrogen gas (N2) and iodine gas (I2): \[ 2 \text{NI}_3 \rightarrow \text{N}_2 + 3 \text{I}_2 \] The iodine gas (I2) is known to have a violet or purple color. ### Step 4: Conclusion From the analysis, we can conclude that: - The brown precipitate formed is nitrogen triiodide (NI3). - The colored gas released upon disturbance is iodine (I2), which appears violet or purple. Thus, the precipitate and colored gas are respectively: - Precipitate: NI3 - Colored gas: I2 ### Final Answer: The precipitate is nitrogen triiodide (NI3) and the colored gas is iodine (I2). ---
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