Volume of a gas at $STP$ is $1.12 \times 10^{-7} \ cc$. Calculate the number of molecules in it.

The number of atoms in $4.25 \ g$ of $NH_3$ is approximately

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.

Maximum number of molecules will be in $:-$

The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is $1 : 4$. The ratio of the number of their molecules is:

The number of atoms in $8 \ g$ of sodium is $x \times 10^{23}$. The value of $x$ is ...... (Nearest integer).
$[ \text{Given}: N_{A} = 6.02 \times 10^{23} \ mol^{-1}, \text{Atomic mass of } Na = 23.0 \ u ]$