The concentration of $\mathrm{NO}_{2}$ in the air at $\mathrm{NTP}$ is reported as $0.30$ ppmv $\text{(ppm by volume)}$. The concentration of $\mathrm{NO}_{2} \mathrm{in} \mu \mathrm{g} / \mathrm{m}^{3} \mathrm{is}$ __________ $\text { (rounded off to the nearest integer). }$
[At NTP, temperature }=$298 \mathrm{~K}$, pressure =$1$ atm, and one mole of ideal gas occupies $24.45 \mathrm{L}$]
${\left[\text { Molecular weight of } \mathrm{NO}_{2}=46 \mathrm{~g} / \mathrm{mol}\right]}$
