$A$ mixture has $18 \ g$ of water and $414 \ g$ of ethanol. The mole fraction of water in the mixture is (assume ideal behavior of the mixture):

The total number of molecules of $SO_2Cl_2$ in $13.5 \ g$ of sulfuryl chloride is ..... (in terms of $N_A$) (in $N_A$)

What is the approximate weight of one molecule of methane $(CH_4)$?

The number of water molecules in $250\, mL$ of water is closest to $.....\, \times 10^{23}$.
[Given: density of water is $1.0\, g\, mL^{-1}$; Avogadro's number $= 6.023 \times 10^{23}$]

The total number of electrons present in $18 \ mL$ water (density $= 1 \ g/mL$) is

The weight of $1 \times 10^{22}$ molecules of $CuSO_4 \cdot 5H_2O$ is ........... $g$.