What amount of dioxygen (in gram) contains $1.8 \times 10^{22}$ molecules?

The mass of $4.48 \ dm^3$ of a certain gas is $5.6 \ g$ at $STP$. Assuming ideal behaviour,identify the probable gas from the following.

Find the number of moles of sodium atoms in $6.9 \times 10^{-2} \ kg$ (Atomic mass $= 23 \ g \ mol^{-1}$)

Which one of the following will have the largest number of atoms?
$(i)$ $1 \,g$ $Au_{(s)}$
$(ii)$ $1 \,g$ $Na_{(s)}$
$(iii)$ $1 \,g$ $Li_{(s)}$
$(iv)$ $1 \,g$ of $Cl_{2(g)}$

The volume of a drop of water is $0.0018 \ mL$. The number of water molecules present in two drops of water at room temperature is:

What is the number of carbon atoms present in $0.35 \ mol$ of $C_6H_{12}O_6$?