d
\(\left(\mathrm{c}_{\mathrm{ms}}\right)_{\mathrm{H}_{2}}=1.84 \mathrm{km} / \mathrm{s},\left(\mathrm{c}_{\mathrm{ms}}\right)_{\mathrm{O}_{2}}=?\)

\(\mathrm{M}_{\mathrm{H}_{2}}=2, \mathrm{M}_{\mathrm{O}_{2}}=32\)

\(\Rightarrow \quad\) Rms velocity

\(c_{\mathrm{rms}}=\sqrt{\frac{3 \mathrm{RT}}{\mathrm{M}}}\)

\(\therefore \quad \frac{c_{\mathrm{H}_{2}}}{c_{\mathrm{O}_{2}}}=\sqrt{\frac{\mathrm{M}_{\mathrm{O}_{2}}}{\mathrm{M}_{\mathrm{H}_{2}}}}\)

\(\Rightarrow \quad \frac{1.84}{C_{O_{2}}}=\sqrt{\frac{32}{2}}=4\)

\(\Rightarrow \quad C_{O_{2}}=\frac{1.84}{4}=0.46 \mathrm{km} / \mathrm{s}\)