Home
Class 12
CHEMISTRY
The unique behaviour of CU, having a pos...

The unique behaviour of CU, having a positive `E^(@)` (reduction potential) accounts for its inability to liberate `H_(2)` from acids,. Only oxidising acids (nitric acid and hot concentrated sulphuric acid) react with Cu. The high energy of transform Cu(s) to `Cu^(2+)(aq.)` is not balanced by its hydration enthalpy.
On the other hand, All Cu(II) halides are known except iodide. in this case, `Cu^(2+)` oxidises `I^(-)` to `I_(2)`:
`2Cu^(2+)+4I^(-) to 2CuI(s)+I_(2)`
However, copper (I) compounds are unstable in aqueous solution annd undergo disproportionation.
`2Cu^(+)(aq.)toCu^(2+)(aq.)+Cu`
The stability of `Cu^(2+)(aq.)` rather than `Cu^(+)(aq)` is due to the much more negative `Delta_(Hyd)` of `Cu^(2+)(aq.)` than `Cu^(+)(aq.)`
Q. Consider the following transformation:
`CuSO_(4)(aq.)+KI(excess)to`product
Select the correct statement:

A

Product contains `[Cu(H_(2)O_(4))]^(2+)` ion.

B

Presence of brown colouration in product is due to `I_(3)^(-)` ion

C

Oxidation state of sulphur in reactant and product is different

D

white ppt. of `CuI_(2)` is observed in product

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given question, we need to analyze the reaction between copper(II) sulfate (CuSO₄) and potassium iodide (KI) in excess. Let's break down the steps to arrive at the correct answer. ### Step 1: Write the Reaction The reaction between CuSO₄ and KI can be written as: \[ \text{CuSO}_4(aq) + 2 \text{KI}(aq) \rightarrow \text{CuI}(s) + \text{I}_2(aq) + \text{K}_2\text{SO}_4(aq) \] ### Step 2: Identify the Products From the reaction, we can identify the products: - Copper(I) iodide (CuI) which is a white precipitate. - Iodine (I₂) which is responsible for the brown coloration in the solution. - Potassium sulfate (K₂SO₄) remains in the solution. ### Step 3: Analyze the Statements Now, let's analyze the statements provided in the question: 1. **Product contains CuH₂O₄**: This is incorrect. The product does not contain CuH₂O₄. 2. **Presence of brown coloration in product is due to I₃⁻**: This is correct. The brown color is due to the formation of I₂ from the oxidation of iodide ions (I⁻). 3. **Oxidation state of sulfur in reactant and product is different**: This is incorrect. The oxidation state of sulfur in both CuSO₄ and K₂SO₄ remains +6. 4. **PPT of CuI₂ is observed in the product**: This is incorrect. The precipitate formed is CuI, not CuI₂. ### Conclusion Based on the analysis: - The correct statement is: "Presence of brown coloration in product is due to I₃⁻." ### Final Answer The correct option is the one that states the presence of brown coloration due to I₃⁻. ---

To solve the given question, we need to analyze the reaction between copper(II) sulfate (CuSO₄) and potassium iodide (KI) in excess. Let's break down the steps to arrive at the correct answer. ### Step 1: Write the Reaction The reaction between CuSO₄ and KI can be written as: \[ \text{CuSO}_4(aq) + 2 \text{KI}(aq) \rightarrow \text{CuI}(s) + \text{I}_2(aq) + \text{K}_2\text{SO}_4(aq) \] ### Step 2: Identify the Products From the reaction, we can identify the products: ...
Promotional Banner

Topper's Solved these Questions

  • TYPES OF REACTIONS

    VK JAISWAL ENGLISH|Exercise ONE OR MORE ANSWERS IS/ARE CORRECT|40 Videos
  • TYPES OF REACTIONS

    VK JAISWAL ENGLISH|Exercise MATCH THE COLUMN|14 Videos
  • TYPES OF REACTIONS

    VK JAISWAL ENGLISH|Exercise LEVEL 2|196 Videos
  • s-BLOCK ELEMENTS

    VK JAISWAL ENGLISH|Exercise SUBJECTIVE PROBLEMS|2 Videos

Similar Questions

Explore conceptually related problems

The unique behaviour of CU, having a positive E^(@) (reduction potential) accounts for its inability to liberate H_(2) from acids,. Only oxidising acids (nitric acid and hot concentrated sulphuric acid) react with Cu. The high energy of transform Cu(s) to Cu^(2+)(aq.) is not balanced by its hydration enthalpy. On the other hand, All Cu(II) halides are known except iodide. in this case, Cu^(2+) oxidises I^(-) to I_(2) : 2Cu^(2+)+4I^(-) to 2CuI(s)+I_(2) However, copper (I) compounds are unstable in aqueous solution annd undergo disproportionation. 2Cu^(+)(aq.)toCu^(2+)(aq.)+Cu The stability of Cu^(2+)(aq.) rather than Cu^(+)(aq) is due to the much more negative Delta_(Hyd) of Cu^(2+)(aq.) than Cu^(+)(aq.) Q. Select the correct chemical change:

All Cu(II) halides are known except the iodide. The reason for it is that

Assertion (A) Cu (II) iodide is not known. Reason (R ) Cu^(2+) oxidises I^(-) to iodine.

Assertion (A) Cu^(2+) iodide is not known. Reason (R ) Cu^(2+) oxidises I^(-) to iodine.

Assertion: Aquated copper(I) cation undergoes disproportionation as: 2Cu^(+)(aq) to Cu^(2+)(aq)+Cu Reason: Hydration energy of Cu^(2+) is higher than that of Cu^(+) which compensates second ionisation energy of Cu.

Assertion: Aquated copper(I) cation undergoes disproportionation as: 2Cu^(+)(aq) to Cu^(2+)(aq)+Cu Reason: Hydration energy of Cu^(2+) is higher than that of Cu^(+) which compensates second ionisation energy of Cu.

Cu^(2+)(aq.) is unstable in solution and under goes simultaneous oxidation and reduction according to the reaction 2Cu^(+)(aq.)hArr Cu^(2+)(aq.)+Cu(s) Choose the correct E^(@) for the above reaction if E_(Cu^(2+))^(@)//Cu = 0.34 V and E_(Cu^(2+))^(@)//Cu^(+) = 0.15 V

The reduction potential diagram for Cu in acid solution is : Calculate X . Does Cu^(+) disproportionate in solution ?

Cu^(+) ion is not stable in aqueous solution because because of dispropotionation reaction. E^(@) value of disproportionation of Cu^(+) is [E_(Cu^(2+)//Cu^(+))^(@)=+ 0.15 V, E_(Cu^(2+)//Cu)^(@)=0.34 V]

VK JAISWAL ENGLISH-TYPES OF REACTIONS-LEVEL 3
  1. Q. Compound 'X' is:

    Text Solution

    |

  2. Q. Incorrect statement 'Y' changes on heating:

    Text Solution

    |

  3. The unique behaviour of CU, having a positive E^(@) (reduction potenti...

    Text Solution

    |

  4. The unique behaviour of CU, having a positive E^(@) (reduction potenti...

    Text Solution

    |

  5. Q. When H(2)S gas was passed into filtrate (P), a coloured precipitate...

    Text Solution

    |

  6. Q. Precipitate (Q) was treated withdil. HCl and coloured solution was ...

    Text Solution

    |

  7. Q. Species P and S are respectively:

    Text Solution

    |

  8. Q. 'T' cannot be identify by:

    Text Solution

    |

  9. Consider three P, Q, R, salts among them P and Q salts have different ...

    Text Solution

    |

  10. Consider three P, Q, R, salts among them P and Q salts have different ...

    Text Solution

    |

  11. Consider three P, Q, R, salts among them P and Q salts have different ...

    Text Solution

    |

  12. Three compound X, Y and Z were taken into three different laboratory v...

    Text Solution

    |

  13. Three compound X, Y and Z were taken into three different laboratory v...

    Text Solution

    |

  14. Three compound X, Y and Z were taken into three different laboratory v...

    Text Solution

    |

  15. In salts of polyatomic anion, as polarising power of cation increase, ...

    Text Solution

    |

  16. In salts of polyatomic anion, as polarising power of cation increase, ...

    Text Solution

    |

  17. Dioxygen directly reacts with nearly all metals annd non-metals except...

    Text Solution

    |

  18. Dioxygen directly reacts with nearly all metals annd non-metals except...

    Text Solution

    |

  19. Dioxygen directly reacts with nearly all metals annd non-metals except...

    Text Solution

    |

  20. Consider the following reactions and answer the following questions. ...

    Text Solution

    |