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The temperature at which CO_{2} has the same R.M.S. speed to that of O_{2} at S.T.P. is/are :

${\left({U}_{r.m.s}\right)}_{C{O}_{2}}={\left({U}_{rms}\right)}_{{O}_{2}}\phantom{\rule{0ex}{0ex}}\sqrt{\frac{3RT}{44}}=\sqrt{\frac{3R\times 273}{32}}\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}T=375K$

Hope this helps,

Regards

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