Why is Fe³⁺ stable, whereas Mn³⁺ is unstable in acidic solution?

1. O₂ oxidises Mn²⁺ to Mn³⁺
2. O₂ oxidises both Mn⁺² to Mn⁺³ and Fe²⁺ to Fe³⁺
3. Fe³⁺ oxidises H₂O to O₂
4. Mn³⁺ oxidised H₂O to O₂

Which of the following statements about Re–Re bonding in [Re₂X₈]²⁻ is incorrect?

Choose the correct statement regarding bonding in FeCl₃ at high temperature.

(I) It contains a 2c-2e- bond.

(II) It contains a 3c-2e- bond.

(III) It contains a coordinate bond.

1. (I), (II)

2. (I), (III)

3. (II), (III)

4. (I), (II) & (III)

 Given lanthanoid ions ,the tendency to form the complexes is highest for:

1. Ce⁺³

2. Pm⁺²

3. Lu⁺³

4. Eu⁺²

The fusion of chromite ore (FeCr₂O₄) with Na₂CO₃ in air gives a yellow solution upon the addition of water. Subsequent treatment with H₂SO₄ produces an orange solution.

The yellow and orange colours, respectively, are due to the formation of:

1. Na₂CrO₄ and Na₂Cr₂O₇

2. Cr(OH)₃ and Na₂Cr₂O₇

3. Cr₂(CO₃)₃ and Fe₂(SO₄)₃

4. Cr(OH)₃ and Na₂CrO₄

Which of the following statements is false? 

Dimethyl glyoxime in a suitable solvent was refluxed for 10 minutes with pure pieces of nickel sheet, it will result in

1. Red precipitate

2. Blue precipitate

3. Yellow precipitate

4. No precipitate

Which of the following is the correct order of second ionization energy?

1. V > Cr > Mn

2. V < Cr < Mn

3. V < Cr > Mn

4. V > Cr < Mn

The inner transition element is not represented by the atomic number among 59, 74, 95, 102, and 104.

1. 59

2. 95

3. 102

4. 104

Find the ion corresponding to a magnetic moment of 3.9 B.M.

1. Fe⁺³

2. Mn⁺²

3. Co⁺²

4. Cu⁺²