The mass of $112 \ cm^3$ of $CH_4$ gas at $STP$ is ............. $g$.

Find the maximum number of atoms in the following:
$(i)$ $1 \ g$ $Au_{(s)}$
$(ii)$ $1 \ g$ $Na_{(s)}$
$(iii)$ $1 \ g$ $Li_{(s)}$
$(iv)$ $1 \ g$ $Cl_{2(g)}$

The number of $Cl^{-}$ ions in $333 \ g$ of anhydrous $CaCl_2$ will be ................ $N_A$.

What is the number of moles of oxygen atoms and the number of moles of $N$ atoms respectively present in one mole of thymine?

From $44 \ mg$ of $CO_2$,$2 \times 10^{20}$ molecules of $CO_2$ are removed. The number of molecules of $CO_2$ left are (Given $N_A = 6 \times 10^{23}$):-

Two vessels $A$ and $B$ of $1 \, L$ each contain $0.11 \, g$ $CO_2$ gas and $0.07 \, g$ of unknown gas respectively under the same conditions of pressure and temperature. The unknown gas is: