Number of atoms in $11.2 \, L$ of $CO_2$ at $NTP$ is .............. $N_A$

Which one of the following has the same number of atoms as are in $6 \,g$ of $H_2O$?

In which of the following pairs do $1 \text{ g}$ of each contain the same number of molecules?
$(I)\, N_2O$ and $CO$               $(II)\,N_2$ and $CO_2$
$(III)\, N_2$ and $CO$                $(IV) \,N_2O$ and $CO_2$

What is the total number of neutrons present in $1.7 \ g$ of ammonia $(NH_3)$?

What is the total number of electrons present in one mole of ethane?

Find the number of molecules present in $70 \text{ g}$ of dinitrogen $(N_2)$.