If the number of moles of $CH_4$ is equal to the number of moles of $1.24 \, g$ of $SO_2$,then the weight of $CH_4$ will be ............ $g$.

$6.02 \times 10^{20}$ molecules of urea are present in $200 \ mL$ of its solution. The concentration of urea solution is .............. $M$

Natural abundances of $^{12}C$ and $^{13}C$ isotopes of carbon are $99\,\%$ and $1\,\%$,respectively. Assuming they only contribute to the molecular weight of $C_2F_4$,the percentage of $C_2F_4$ having a molecular mass of $101$ is $.....$

Calculate the number of molecules in a gas sample having a volume of $1.12 \times 10^{-7} \, cc$ at $NTP$.

Find the number of moles of sodium atoms in $6.9 \times 10^{-2} \ kg$ (Atomic mass $= 23 \ g \ mol^{-1}$)

Assertion $(A)$: Equal moles of different substances contain the same number of constituent particles.
Reason $(R)$: Equal weights of different substances contain the same number of constituent particles.
The correct answer is