We’re rewarding the question askers & reputations are being recalculated! Read more.
11

Usually the dot is put there to emphasize that the nitric oxide is a free radical that includes an unpaired electron. This is especially notable by comparison with $\ce{NO^+}$, which does not have the unpaired electron. Note that the nomenclature $\ce{·NO}$ should not be rendered as showing the unpaired electron on nitrogen. The unpaired electron is ...


5

It is not necessary, but optional, to express explicitly the radical status. In other cases, like alkyl radicals, the dot marking is mandatory, not to be confused e.g. with a functional group. For curiosity, the ground state of the oxygen molecule - triplet oxygen - is a biradical, with 2 unpaired electrons. What we write as $\ce{O=O}$ is singlet oxygen, ...


4

For "burning" of paper by sulphuric acid, the better term would be "aggressive dehydration". Note that aqua regia is rather a diluted acidic mixture without significant dehydrating or oxygen based oxidation behaviour, but manifests aggressive chloration behaviour, that dissolves precise metals. Cellulose has quite good endurance against chlorine, which is ...


4

It would be a total waste of energy. Remember that the Sun is sending orders of magnitude more energy than humanity can produce. A significant fraction of that is UV, so the Sun is already breaking up more Methane than humanity could do by adding laser diodes or whatnot. We might be able to do more at the ground, where the Sun's UV is mostly filtered. It ...


4

It is difficult to comment on such a broad statement because often it depends on the specifics. So instead, I will talk about a single example: Will the HCl molecule dissociate into radicals (atoms, in this case) or ions? $$\tag{1}\ce{H-Cl -> H+ + Cl-}$$ $$\tag{2}\ce{H-Cl -> H. + Cl.}$$ Under many circumstances, neither (1) nor (2) happens, H-Cl is ...


4

Nitric oxide ($\ce{NO}$) is a free radical and hence why that dot is for. Explanation for the dot and the reason why its there have been well answered in other responses. Nevertheless, I decided to put the molecular orbital representation of $\ce{NO}$ as depicted below for your convenience (Ref.1): There are three electrons in antibonding orbitals and ...


3

The radical monobromination of bicyclo[2.2.1] heptane could give $\ce{1}$ ,$\ce{2}$ and $\ce{3}$. However , $\ce{2}$ and $\ce{3}$ , are unstable .On observing $\ce{2}$ , planar radical at bridgehead is unstable due to angular strain introduced by planarity of radical at bridgehead . Similarly in $\ce{3}$ , due to angular strain introduced in to the ...


2

Before make any suggestion for the sought cyclization mechanism, let’s look at some rules and guidelines set by peers in their early studies on radical cyclizations. Specifically, Beckwith and coworkers have set few guidelines for radical reactions, which involves intramolecular cycloaddition reactions (Ref.1). During their kinetic studies on various en-yl ...


2

Powerful ground lasers are surely inefficient. The radicals are created in close proximity, meaning they likely have a good chance to recombine. Also highpower lasers (or any strong light source) are generally not very efficient. A lot of small ones would be better. I would mount simple UV LEDs on the underside of passenger planes, where they are switched ...


1

Concentrated and strong acids like sulfuric acid are substances that extracts water anywhere and everywhere to react with and make H3O+ ions. They are even able to extract water from the cellulose of the paper, as cellulose is made of carbon plus water. So a drop of sulfuric acid on paper burns it, or rather transforms it into charcoal. The word "burn" is ...


1

The dot represents an unpaired electron. It's written that way as a reduced Lewis dot diagram. The reduction works like this: Start with the typical dot-diagrams for Nitrogen and Oxygen atoms, i.e.$$ \begin{array}{ccc} \textbf{Nitrogen} & \qquad & \textbf{Oxygen} \\[-10px] {\Huge{\begin{array}{rcl} & \cdot \phantom{\cdot} \\[-50px] \...


1

but how do ions have unpaired electrons when an ion has all its electrons paired either by loosing or gaining electrons to attain the nearest noble gas configuration? (Quote from your question, emphasis mine) Your fallacy is the word I emphasised. Surely it is often taught like that—especially in introductory chemistry—that when ions are generated the ...


Only top voted, non community-wiki answers of a minimum length are eligible