What is the mass of potassium chloride produced when $12.25 \ g$ of potassium chlorate undergoes decomposition (in $g$)? (Atomic masses: $K=39, Cl=35.5, O=16$)

The amount of $KMnO_4$ required to prepare $100 \ mL$ of $0.1 \ N$ solution in alkaline medium is ............... $g$.

$25 \ cm^3$ of oxalic acid completely neutralized $0.064 \ g$ of sodium hydroxide. The molarity of the oxalic acid solution is: (in $M$)

What volume of $CO_2$ at $STP$ is obtained by thermal decomposition of $20 \ g$ $KHCO_3$? [Atomic weight of $K = 39$]
$2KHCO_{3(s)} \to K_2CO_{3(s)} + CO_{2(g)} + H_2O_{(g)}$

Number of moles of methane required to produce $22 \ g$ $CO_{2(g)}$ after combustion is $x \times 10^{-2}$ moles. The value of $x$ is

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ $3.1500 \ g$ of hydrated oxalic acid dissolved in water to make $250.0 \ mL$ solution will result in $0.1 \ M$ oxalic acid solution.
Reason $R:$ Molar mass of hydrated oxalic acid is $126 \ g \ mol^{-1}$.
In the light of the above statements,choose the correct answer from the options given below: