Calculate the number of total atoms and molecules in $4 \, L$ of $SO_2$ gas at $350 \, K$ temperature and $10^3 \, Pa$ pressure. $[R = 8.3144 \, J \, K^{-1} \, mol^{-1}]$.

(N/A) Using the ideal gas equation $PV = nRT$:
$n = \frac{PV}{RT} = \frac{10^3 \, Pa \times 4 \times 10^{-3} \, m^3}{8.3144 \, J \, K^{-1} \, mol^{-1} \times 350 \, K} \approx 1.374 \times 10^{-4} \, mol$.
Number of molecules $= n \times N_A = 1.374 \times 10^{-4} \times 6.022 \times 10^{23} \approx 8.275 \times 10^{19} \, \text{molecules}$.
Since each $SO_2$ molecule has $3$ atoms,total atoms $= 3 \times 8.275 \times 10^{19} \approx 2.483 \times 10^{20} \, \text{atoms}$.