Practicing Success
Practicing Success
CUET Preparation Today
Which of the following statements are correct? A. \(CuI_2\) is not known B. \(Cu_2I_2\) is known C. \(Cu^{2+}\) ion oxidizes \(I^-\) to \(I_2\) D. \(Cu^{2+}\) ion does not oxidize \(I^-\) to \(I_2\) Choose the correct answer from the options given below: |
B and D only A, C and D only B, C and D only A, B, C and D only |
B, C and D only |
The correct answer is 3. B, C and D only. Statement A: Copper(II) iodide \((CuI_2)\) is a known compound. It is a dark brown solid that is insoluble in water. Statement B: Copper(I) iodide \((Cu_2I_2)\) is also a known compound. It is a white solid that is soluble in water. Statement C: Copper(II) ion \((Cu^{2+})\) can oxidize iodide ion \((I^-)\) to iodine \((I_2)\). The balanced chemical equation for this reaction is: \(2 Cu^{2+} + 4 I^- \longrightarrow 2 CuI + I_2\)Statement D: Copper(II) ion \((Cu^{2+)}\) does not oxidize iodide ion \((I^-)\) to iodine \((I_2)\) under standard conditions. This is because the standard reduction potential of the iodine/iodide couple (E° = 0.54 V) is more positive than the standard reduction potential of the copper(II)/copper(I) couple (E° = 0.34 V). This means that iodine is a stronger oxidizing agent than copper(II), and so iodine will not be reduced to iodide by copper(II). Therefore, the correct statements are B, C and D only. |
