What is the total number of carbon atoms present in $n$ mole of citric acid (in $n$)?

In which case is the number of molecules of water maximum?

$A$ sample of phosphorus trichloride $(PCl_3)$ contains $1.4$ moles of the substance. How many atoms are there in the sample?

The number of molecules in $4.25 \ g$ of ammonia is approximately

Choose the correct option for the mole fraction of both components in a gaseous mixture containing $7 \ g$ of nitrogen and $8 \ g$ of oxygen.

The atomic weights of two elements $A$ and $B$ are $40$ and $80$ respectively. If $x \ g$ of $A$ contains $y$ atoms,how many atoms are present in $2x \ g$ of $B$?