Calculate the number of moles in $11.2 \ L$ of oxygen gas at $STP$.

$138 \ g$ of ethyl alcohol is mixed with $72 \ g$ of water. The ratio of mole fraction of alcohol to water is

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.

Calculate the number of molecules present in $2.24 \text{ dm}^3$ of carbon dioxide $(CO_2)$ at $STP$.

Containers $A, B$,and $C$ of equal volume contain oxygen,neon,and methane gases respectively at the same temperature and pressure. Which of the following is the correct order of their increasing mass?

What is the number of moles and total number of atoms respectively present in $5.6 \ cm^{3}$ of ammonia gas at $STP$?