Sum of $\pi$-bonds present in peroxodisulphuric acid and pyrosulphuric acid is

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R

Assertion A :- Carbon forms two important oxides $\mathrm{CO}$ and ${\mathrm{CO}}_2$. $\mathrm{CO}$ is neutral whereas ${\mathrm{CO}}_2$ is acidic in nature.

Reason R :  ${\mathrm{CO}}_2$ can combine with water in a limited way to form carbonic acid, while $\mathrm{CO}$ is sparingly soluble in water.

In the light of the above statements, choose the most appropriate answer from the options given below :-

Given below are two statements:

Statement I: The decrease in first ionization enthalpy from $\mathrm{B}$ to $\mathrm{Al}$ is much larger than that from $\mathrm{Al}$ to $\mathrm{Ga}$.

Statement II: The d orbitals in $\mathrm{Ga}$ are completely filled.

In the light of the above statements, choose the most appropriate answer from the options given below

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

Assertion (A): In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags.

Reason (R): Silica gel adsorbs moisture from air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning.

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