# Tag Info

## Hot answers tagged oxidation-state

35

According Kinetics, Mechanism, and Spectroscopy of the Reversible Binding of Nitric Oxide to Aquated Iron(II). An Undergraduate Text Book Reaction Revisited The correct structure is $\ce{ [Fe^{III}(H_2O)_5(NO^{-})]^{2+} }$ For many years it was thought that iron was reduced to $\ce{Fe^{I}}$ and $\ce{NO}$ oxidized to $\ce{NO+}$, based upon an observed ...

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Actually, in theory almost all of the elements can be found with both positive and negative oxidation numbers: it's just a matter of finding a system with the proper reagents and conditions to force it. If you isolate chemical species which have a very strong tendency of displaying some specific behaviour (accepting electrons, donating electrons, ...

28

Until the (recent) redefinition of the IUPAC, the concept of oxidation states was not as well defined as one would expect. I have discussed the issues of the old version and outlined the new definition in more detail in an answer to Electronegativity Considerations in Assigning Oxidation States. When you apply the official pre-2016 definition (via the ...

27

In the course of searching for examples of usage of the "-osic" suffix, I think I found the answer to my own question. From the last link in the question, a web store selling pigments (emphasis added): The source of natural black oxide usually is from an iron ore called magnetite. Magnetite, also known as lodestone, is a ferrous ferric oxide (ferrosic ...

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It depends. Consider various radicals such as the superoxide anion $\ce{O2^{.-}}$ or $\ce{NO2^{.}}$. For both of these, we can draw simple Lewis representations: In these structures, the oxygen atoms would have different oxidation states ($\mathrm{-I}$ and $\pm 0$ for superoxide, $\mathrm{-II}$ and $\mathrm{-I}$ for $\ce{NO2}$). That is the strict, ...

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TL;DR; Oxidation States are useful tools used in nomenclature, redox chemistry etc. There are a few simplistic rules to determine the oxidation state of elements in an atom; but they're not applicable to all the cases. There are instances where the assignment of oxidation state isn't useful, or where the oxidation state is ambiguous. We're easier off ...

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Your basic assumption is incorrect: the iron in [Fe(H2O)5(NO)]2+ is Fe(III), and the ligand is NO–.

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Excursion into simple coordination chemistry: Bonding, backbonding and simple orbital schemes Please refer to Breaking Bioinformatic’s answer for the MO scheme of carbon monoxide, it is very helpful. You might also look at the orbital pictures in this answer by Martin. Carbon monoxide can bind to metal centres via a σ coordinative bond where the HOMO ...

23

On negative oxidation states, in general Although it's usually a topic that's covered relatively late in a chemistry education, negative oxidation states for transition metals[1] are actually quite alright. On the Wikipedia list of oxidation states, there are quite a number of negative oxidation states. Some textbooks have tables which only show positive ...

21

Atomic copper has the electron configuration $\ce{[Ar] 3d^{10} 4s^1}$. By removing one electron and producing $\ce{Cu^{+1}}$, an inert gas configuration $\ce{[Ar] 3d^{10} 4s^0}$ is produced. While it does take a lot more energy to remove the second electron from copper (first IP=745 kJ/mol, second IP=1,958 kJ/mol), if this energy can be offset by the ...

19

The "oxidation number" is a theoretical value used to do electron bookkeeping and is one way of comparing the number of electrons "owned" by an atom in a molecule or ion versus how many valence electrons present in the atom as depicted on the periodic table. Your calculation is assuming that all of the carbon atoms in octane have the same oxidation state, ...

19

In the IUPAC Recommendations 2016 the definition of oxidation state underwent a significant and comprehensive change. It does now resemble the version wich was proposed be Hans-Peter Loock and is quoted in the earlier version of this answer, parts of which are included below. The electronegativity battle scheme is most helpful for all kinds of compounds ...

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According to Oxidation state of sulfur in thiosulfate and implications for anaerobic energy metabolism according to the currently held view, the two sulfur atoms of thiosulfate exist in the oxidation state of sulfate (+6) and sulfide (−2) and do not change their respective oxidation states upon disproportionation. Our results based on XANES spectroscopy ...

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This is yet another interesting effect of the anomalous compactness of orbitals in the first appearance of each type of subshell ($1s$, $2p$, $3d$, $4f$, $5g$, etc). The solutions to the Schrödinger equation for electron wavefunctions in hydrogen-like atoms are such that these subshells are composed of orbitals with no radial nodes. This means the electrons ...

16

The formula of $\ce{Fe3O4}$ is a shorthand for $\ce{Fe^{II}Fe^{III}2O4}$, so there are two sorts of atoms of iron here in +2 and +3 oxidation state. However, it is still possible to gain truly fractional oxidation states. The simplest example probably would be potassium superoxide, $\ce{KO2}$. Here, the anion is symmetrical $\ce{O2^{-}}$ anion, so obviously ...

16

The answer has to do with pi-backbonding. In essence, the CO molecule has a negative formal charge on the carbon (it's neutral because of the oxygen having a positive formal charge). However, C is quite electropositive, and would like to relieve the stress caused by the negative formal charge. To relieve the stress caused by the negative charge, the CO ...

16

I feel very ashamed to answer my own question, but having found a possible answer, I don’t see why I shouldn’t share it with the community. I would like to start by bringing in this table of orbital energies (from the appendix I linked to in the question) as a reference point for further explanations: $$\begin{array}{ccc} \hline \text{Element} & \text{... 16 tl;dr The ambiguity is due to an unfortunate incompleteness of the previously (prior to 2016) existing rules. The oxidation state of fluorine in \ce{FNO3} is -1 according to the present rules. As a general reminder, it is important to understand, that oxidation states are a bookkeeping tool only, and that they hardly represent the general bonding in ... 15 I am not sure if Silane (\ce{SiH_4}) can really be considered. But there are silicides which silicon forms with strongly electropositive metals. In these compounds, silicon has a negative oxidation state. For magnesium silicide - \ce{Mg_2Si}, the oxidation state of silicon would be -4. 15 Thallium triiodide does exist and it is formulated as \ce{Tl+I3-} and not \ce{Tl^3+(I^{-})3}. Thus \ce{TlI3} is a thallium(I) compound and contains the triiodide ion, \ce{I3^{−}}. This is confirmed by considering the standard potential which indicate that \ce{Tl(III)} is rapidly reduced to \ce{Tl(I)} by the iodide.$$\begin{align} \ce{Tl^3+ + ...

14

Whether sulfur or phosphorous actually expand their octet is contested within the chemistry community. Another term for this octet expansion is "hypervalency." You can find many works of research regarding hypervalency. The consensus, according to Wikipedia, is that both can expand their octets, but not to a significant extent. In other words, d-orbital ...

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It's not obvious, but common oxidation state for gold is +3. It caused by destabilization of the $5d^{10}$ orbital. Detailed explanation you can find in The Chemistry of Gold, in Chapter 1.1.3.

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There is no anomaly in here. Fluorine’s oxidation state in $\ce{HOF}$ is $\mathrm{-I}$ as the theory says. Hydrogen’s is $\mathrm{+I}$. This leaves oxygen with an oxidation state of $\mathrm{\pm 0}$. That final fact is where the oxidative power comes from. Oxygen, the second-most electronegative element in the periodic table, has the same oxidation state as ...

12

Hint : n-factor of a molecule/compound is defined as the change in oxidation state per molecule. You have correctly calculated the change of one carbon atom as 4. But how many carbon atoms are there in the glucose molecule? Note: The average oxidation state of carbon in glucose is zero while in reality the different carbons have different OS. (...

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Nicolau Saker Neto already has an excellent answer, but he doesn't mention possibly the most common instance of an element being both a anion and a cation: Hydrogen Hydrogen usually has a positive oxidation state, but in any of the metal hydrides, such as sodium hydride, it takes on a negative oxidation state.

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Yes, they can show oxidation states lower than -1. For example in hyperlithiated compounds, like $\ce{Li3Cl}$, the chlorine would formally have an oxidation state of -3. However, a word of caution, oxidation states are a tricky thing. They are determined by adopting the hypothetical view that the compound you are looking at consists only of single-atomic ...

11

Ammonium sulfate is an ionic compound, composed of two ammonium ions ($\ce{NH_{4}^{+}}$) and one sulfate ion ($\ce{SO_{4}^{2-}}$). As such, you can neglect the sulfate entirely from your consideration of the oxidation state of the nitrogen, as well as treating each ammonium ion as a separate entity. Given the total charge on the ammonium cation, it should be ...

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Oxygen can take multiple oxidation states. This particular compound is sodium peroxide. You're right that usually oxygen has a charge of -2, but in this case, there's no way that each $\ce{Na}$ can have an oxidation state of +2. So you then work backwards, deciding if it's $\ce{Na+}$ then you have +2 from the sodium, and oxygen must have an average ...

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I appreciate above answer by BreakingBioinformatics. However I have been looking for the oxidation reactions involving Fe in this case. Found some useful material here. It is based on the textbook, Chemistry: Principles, Patterns, and Applications, 2007, Bruce Averill, Patricia Eldredge. Note : Following picture only shows the binding of Myoglobin. Here'...

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