The amount of oxygen in $3.6 \, \text{moles}$ of water is ............ $g$.

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 number of oxygen atoms in $8 \ g$ of ozone $(O_3)$?

$6.02 \times 10^{20}$ molecules of urea are present in $200 \ mL$ of its solution. The concentration of urea solution is .............. $M$

$A$ thin layer of cobalt is deposited on a plate with a total area of $0.5 \ m^2$ and a thickness of $0.005 \ cm$. How many cobalt atoms are deposited on the plate? (Density of cobalt $= 8.9 \ g \ cm^{-3}$,Atomic mass of $Co = 59 \ g \ mol^{-1}$)

The number of hydrogen atoms in $0.9 \ g$ glucose $(C_6H_{12}O_6)$ $(M_w = 180 \ g/mol)$ is same as