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A certain compound (X) when treated with...

A certain compound `(X)` when treated with copper sulphate solution yields a brown precipitate. On adding hypo solution the precipitate turns white. The compound is

A

`K_2CO_3`

B

Kl

C

KBr

D

`K_3PO_4`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the reactions that occur when compound (X) is treated with copper sulfate (CuSO4) and hypo solution (Na2S2O3). ### Step-by-Step Solution: 1. **Identify the Reaction with Copper Sulfate**: - When compound (X) is treated with copper sulfate solution, it yields a brown precipitate. This indicates that the compound likely contains iodide ions (I⁻) because copper(II) ions (Cu²⁺) react with iodide to form cupric iodide (CuI2), which is brown in color. 2. **Formation of Brown Precipitate**: - The brown precipitate formed is due to the presence of iodine (I2) in the solution. The reaction can be represented as: \[ 2KI + CuSO_4 \rightarrow CuI_2 \downarrow + K_2SO_4 \] - Here, CuI2 is unstable and can decompose to form CuI (cuprous iodide), which is white. 3. **Reaction with Hypo Solution**: - When hypo solution (Na2S2O3) is added to the brown precipitate, it turns white. This is because hypo solution reduces iodine (I2) to iodide ions (I⁻), which are colorless. The reaction can be represented as: \[ I_2 + 2Na_2S_2O_3 \rightarrow Na_2S_4O_6 + 2NaI \] - This reaction removes the iodine from the solution, leading to a loss of color. 4. **Conclusion**: - Given that the compound (X) is potassium iodide (KI), which reacts with copper sulfate to produce the brown precipitate (due to I2 formation) and then turns white upon the addition of hypo solution, we conclude that the compound is potassium iodide. ### Final Answer: The compound (X) is **Potassium Iodide (KI)**.
To solve the problem, we need to analyze the reactions that occur when compound (X) is treated with copper sulfate (CuSO4) and hypo solution (Na2S2O3). ### Step-by-Step Solution: 1. **Identify the Reaction with Copper Sulfate**: - When compound (X) is treated with copper sulfate solution, it yields a brown precipitate. This indicates that the compound likely contains iodide ions (I⁻) because copper(II) ions (Cu²⁺) react with iodide to form cupric iodide (CuI2), which is brown in color. 2. **Formation of Brown Precipitate**: ...
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