Q 31 :

During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction.       [2023]

• Both aqueous acidic and neutral

   

• Both aqueous acidic and faintly alkaline

   

• Aqueous acidic

   

• Aqueous neutral

   

Q 32 :

In chromyl chloride, the number of d-electrons present on chromium is same as in (Given atomic number of Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26)                [2023]

• Fe (III)

   

• Mn (VII)

   

• Ti (III)

   

• V (IV)

   

Q 33 :

Given below are two statements:

Statement I: Aqueous solution of ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ is preferred as primary standard in volumetric analysis over ${\mathrm{Na}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ aqueous solution.

Statement II: ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ has a higher solubility in water than ${\mathrm{Na}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$.

In the light of the above statements, choose the correct answer from the options given below:                [2023]

• Statement I is true but Statement II is false.

   

• Both Statement I and Statement II are false.

   

• Both Statement I and Statement II are true.

   

• Statement I is false but Statement II is true.

   

Q 34 :

Prolonged heating is avoided during the preparation of ferrous ammonium sulphate to               [2023]

• prevent breaking

   

• prevent reduction

   

• prevent oxidation

   

• prevent hydrolysis

   

Q 35 :

The number of electrons involved in the reduction of permanganate to manganese dioxide in acidic medium is __________.  [2023]

Q 36 :

In alkaline medium, the reduction of permanganate anion involves a gain of __________ electrons.  [2023]

Q 37 :

The total change in the oxidation state of manganese involved in the reaction of ${\mathrm{KMnO}}_4$ and potassium iodide in the acidic medium is __________.  [2023]

Q 38 :

In Chromyl chloride, the oxidation state of chromium is (+) __________.         [2023]

Q 39 :

Choose the correct sets with respective observations:                                     [2025]

(1)  ${\mathrm{CuSO}}_4$ (acidified with acetic acid) + ${\mathrm{K}}_2\mathrm{Fe}{\left(\mathrm{CN}\right)}_6$ (neutralized with NaOH) $\to$ Blue precipitate

(2)  $2{\mathrm{CuSO}}_4+{\mathrm{K}}_2\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\to$ Blue precipitate

(3)  $4{\mathrm{FeCl}}_3+3{\mathrm{K}}_4\mathrm{Fe}{\left(\mathrm{CN}\right)}_6\to \frac{1}{2}{\mathrm{K}}_4\mathrm{Fe}{\left(\mathrm{CN}\right)}_6$

(4)  $37{\mathrm{Cl}}_2+2\mathrm{KFe}{\left(\mathrm{CN}\right)}_6\to 6\mathrm{KCl}$

In the light of the above options, choose the correct set:
 

• (A), (B), (C)

   

• (A), (B), (D)

   

• (C), (D)

   

• (B), (D)

   

Q 40 :

${\mathrm{KMnO}}_4$ acts as an oxidising agent in acidic medium. ‘X’ is the difference between the oxidation states of Mn in reactant and product. ‘Y’ is the number of ‘d’ electrons present in the brown red precipitate formed at the end of the acetate ion test with neutral ferric chloride. The value of $X+Y$ is ____.         [2025]