The number of molecules in $16 \ g$ of methane is

The number of molecules present in $1$ liter of water is: (Density of water = $1 \ g/mL$) (in $N_A$)

How many moles of magnesium phosphate,$Mg_{3}(PO_{4})_{2}$ will contain $0.25 \ mol$ of oxygen atoms?

The number of water molecules is maximum in

In $3$ moles of ethane $(C_{2}H_{6})$,calculate the following:
$i.$ Number of moles of carbon atoms.
$ii.$ Number of moles of hydrogen atoms.
$iii.$ Number of molecules of ethane.

The total number of electrons in $18 \ mL$ of water (density $= 1 \ g \ mL^{-1}$) is