Q 1 :

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: An aqueous solution of KOH when used for volumetric analysis, its concentration should be checked before the use.

Reason R: On aging, KOH solution absorbs atmospheric ${\mathrm{CO}}_2$.

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

• (A) is correct but (R) is not correct

   

• (A) is not correct but (R) is correct

   

• Both (A) and (R) are correct but (R) is not the correct explanation of (A)

   

• Both (A) and (R) are correct and (R) is the correct explanation of (A)

   

Q 2 :

${\mathrm{KMnO}}_4$ is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute ${\mathrm{H}}_2{\mathrm{SO}}_4$. Number of water molecules produced for 2 molecules of ${\mathrm{KMnO}}_4$ is ________.           [2023]

Q 3 :

$x$ mg of pure $\mathrm{HCl}$ was used to make an aqueous solution. 25.0 mL of 0.1 M $\mathrm{Ba}{\left(\mathrm{OH}\right)}_2$ solution is used when the $\mathrm{HCl}$ solution was titrated against it. The numerical value of $x$ is __________ $\times {10}^{-1}$ (Nearest integer).

Given: Molar mass of $\mathrm{HCl}$ and $\mathrm{Ba}{\left(\mathrm{OH}\right)}_2$ are 36.5 and $171.0{\text{\hspace{0.05em}g mol}}^{-1}$ respectively.                 [2026]