What is the mass of $1 \times 10^{22}$ molecules of $CuSO_4 \cdot 5H_2O$?

What is the numerical value of $\frac{N}{n}$? (Where $N$ is the number of molecules in a given gas sample and $n$ is the number of moles of the gas.)

The weight of $112 \ cm^3$ of $CH_4$ gas at $STP$ is ...... $g$.

The number of oxygen atoms in $4.4 \ g$ of $CO_2$ is approximately:

The total number of valence electrons in $4.2 \ g$ of $N_3^-$ ion is ............. $N_A$ ($N_A$ is the Avogadro's number).

The number of moles of sodium oxide in $620 \ g$ of it is ................ $moles$.