Magnetic and acidic properties of nitric oxide

I was faced with the following question:



> 
> **PART C – CHEMISTRY**
> 
> 
> Which one of the following properties is **not** shown by $\ce{NO}$?
> 
> 
> 1. It combines with oxygen to form nitrogen dioxide
> 2. Its bond order is $2.5$
> 3. It is diamagnetic in the gaseous state
> 4. It is a neutral oxide
> 
> 
> 


I am confused about (3) & (4). I know $\ce{NO}$ reacts with water & oxygen to produce $\ce{HNO2}$, and then $\ce{NaOH}$ to produce $\ce{NaNO2, N2O, H2O}$. So, obviously it's acidic.


But there is one unpaired electron in the $\ce{N}$ atom. So, I see no reason for $\ce{NO}$ to be diamagnetic in gaseous state.


But, these questions do not have two correct answers. So, one of them has to be wrong. I am not sure which one.




1. That's true.
2. [The bond order in $\ce{NO}$ is 2.5](https://myaptitude.in/question-bank/chemistry/the-bond-order-in-no-is-2-5-while-that-in-no-is-3)
3. The oxidation state of $\ce N$ is +2, and this is a colourless, **paramagnetic** gas (i.e. it is a radical, or contains an unpaired electron). ([source](http://www.everyscience.com/Chemistry/Inorganic/Group_15/Nitrogen/d.1321.php))
4. **Neutral oxides** are those oxides which show neither basic nor acidic properties when they react with water. Examples include carbon monoxide $(\ce{CO})$ and nitrous oxide $(\ce{N2O})$ which are only slightly soluble in water, and **nitric oxide $\mathbf{(NO)}$** which is appreciably soluble in cold water. ([source](http://glossary.periodni.com/glossary.php?en=neutral%20oxide))


So, option 3 is the correct answer as it is an inaccurate statement.


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