Why doesn't nitric oxide react with water?

Why doesn't $\ce{NO}$ (nitric oxide) react with water? I know it is a neutral oxide, but I'm really curious as to why that is. Why will $\ce{NO}$ not react with $\ce{H2O}$?




Although nitric oxide is thermodynamically unstable, it is kinetically stable as its decomposition rate is very slow[ref] and so it is considered stable and won't normally react to anything. 


So, nitric oxide wouldn't normally hydrolyze easily. But in the presence of air, it forms [nitrous acid](https://en.wikipedia.org/wiki/Nitrous_acid) $(\ce{HONO})$:


$$\ce{4NO + O2 + 2 H2O -> 4 HNO2}$$


However, nitrous acid is very unstable and quickly disproportionates:


$$
\begin{align}
\ce{2 HNO2 &-> NO2 + NO + H2O &(cold dil. soln.)}\\
\ce{3 HNO2 &-> HNO3 + 2 NO + H2O &(warm conc. soln.)}
\end{align}$$


Since $\ce{HNO2}$ is required to prepare [diazonium salts](https://en.wikipedia.org/wiki/Diazonium_compound) (a versatile compound in organic chemistry), it is prepared in-situ by reaction of $\ce{NaNO2}$ and $\ce{HCl}$. Due to its instability, it is prepared for one-time use and is not stored for further preparations.




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**Reference:** *J. Phys. Chem.*, **1958**, *62* (3), pp 360–361 <https://doi.org/10.1021/j150561a030>


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I have also heard about a disproportion reaction which happens with a productivity of around $0,01 \%$ as, 


$$\ce{4NO + H2O -> N2O + 2HNO2}$$


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