We are asked what would happen to the rate if the concentration of NO were increased by a factor of 2.1

Calculate the rate constant, k:

$\overline{){\mathbf{rate}}{\mathbf{}}{\mathbf{=}}{\mathbf{}}{\mathbf{k}}{\mathbf{\left[}\mathbf{NO}\mathbf{\right]}}^{{\mathbf{2}}}\mathbf{\left[}{\mathbf{O}}_{\mathbf{2}}\mathbf{\right]}}\phantom{\rule{0ex}{0ex}}\mathbf{}\mathbf{k}\mathbf{}\mathbf{=}\mathbf{}\frac{\mathbf{rate}}{{\mathbf{\left[}\mathbf{NO}\mathbf{\right]}}^{\mathbf{2}}\mathbf{\left[}{\mathbf{O}}_{\mathbf{2}}\mathbf{\right]}}\mathbf{}\phantom{\rule{0ex}{0ex}}\mathbf{}\mathbf{k}\mathbf{}\mathbf{=}\mathbf{}\frac{\mathbf{9}\mathbf{.}\mathbf{3}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{5}}\mathbf{}\mathbf{}\overline{)\mathbf{M}}\mathbf{/}\mathbf{s}}{{\mathbf{[}\mathbf{4}\mathbf{.}\mathbf{1}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{}\mathbf{M}\mathbf{]}}^{\mathbf{2}}\mathbf{[}\mathbf{3}\mathbf{.}\mathbf{6}\mathbf{\times}{\mathbf{10}}^{\mathbf{-}\mathbf{2}}\mathbf{}\overline{)\mathbf{M}}\mathbf{]}}\mathbf{}$

**k = 1.54 M ^{-2} s**

The reaction 2NO(g) + O_{2} (g) → 2NO_{2} (g) is second order in NO and first order in O_{2}. When [NO]= 4.1×10^{−2} M and [O_{2}]= 3.6×10^{−2} M , the observed rate of disappearance of NO is 9.3×10^{−5} M/s.

What would happen to the rate if the concentration of NO were increased by a factor of 2.1?

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