In a mildly alkaline medium, thiosulphate ion is oxidized by ${\mathrm{MnO}}_4^{-}$ to "A". The oxidation state of sulphur in "A" is:

1.	+4	2.	+2
3.	–2	4.	+6

In basic medium CrO₄²⁻ oxidizes S₂O₃^2– to form S₂O₃²⁻  to form  SO₄²⁻  and itself changes into Cr(OH)₄⁻ . The volume of 0.154 M  CrO₄²⁻ required to react with 40 mL of 0.25 M S₂O₃²⁻ is: 

(Rounded-off to the nearest integer)

1. 178 
2. 173 
3. 169 
4. 181

What is the outer electronic configuration of Gadolinium (\(Gd\)) with atomic number 64?

1.  \(4 f^3~ 5 d^5~ 6 s^2\)

2.  \(4 f^8~ 5 d^0 ~6 s^2\)

3. \(4 f^4~ 5 d^4~ 6 s^2\)

4.  \(4 f^7~ 5 d^1~ 6 s^2\)

In context with the transition elements, which of the following statements is incorrect?

If dichromate ion is treated with base, the oxidation number of Cr in the product formed will be:

1. +6

2. +4

3. +5

4. +2

Lanthanoids does not form MO₂ among the following is-[M is lanthanoid metal]

1. Pr

2. Dy

3. Nd

4. Yb

On treating a compound with warm dil. H₂SO₄, gas X is evolved which turns K₂Cr₂O₇ paper acidified with dil. H₂SO₄ to a green compound Y. X and Y respectively are -

1. $\mathrm{X}={\mathrm{SO}}_2,\mathrm{Y}={\mathrm{Cr}}_2{\mathrm{O}}_3$

2. $\mathrm{X}={\mathrm{SO}}_3,\mathrm{Y}={\mathrm{Cr}}_2{\mathrm{O}}_3$

3. $\mathrm{X}={\mathrm{SO}}_2,\mathrm{Y}={\mathrm{Cr}}_2{\left({\mathrm{SO}}_4\right)}_3$

4. $\mathrm{X}={\mathrm{SO}}_3,\mathrm{Y}={\mathrm{Cr}}_2{\left({\mathrm{SO}}_4\right)}_3$

Given below are two statements:

Statement I: CeO₂ can be used for the oxidation of aldehydes and ketones.

Statement II: Aqueous solution of EuSO₄ is a strong reducing agent.

In the light of the above statements, choose the correct answer from the options given below:

1. Statement I is false but statement II is true

2. Statement I is true but statement II is false

3. Both statement I and statement II are true

4. Both statement I and statement II are false

The lanthanoid that does not show +4 oxidation state is:

The incorrect statement among the following is: 

1. VOSO₃ is a reducing agent.

2. Cr₂O₄ is an amphoteric oxide.

3. RuO₄ is an oxidizing agent.

4. Red color of ruby is due to the presence of Co³⁺.