Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

Questions tagged [oxidation-state]

Oxidation state is a concept, which assigns hypothetical charges to atoms in compounds. This tag should be applied to questions which relate to that concept or to oxidation states in atoms of compounds.

Filter by
Sorted by
Tagged with
48
votes
8answers
54k views

Is iron in the brown ring compound in a +1 oxidation state?

In the standard brown ring test for the nitrate ion, the brown ring complex is: $$\ce{[Fe(H2O)5(NO)]^{2+}}$$ In this compound, the nitrosyl ligand is positively charged, and iron is in a $+1$ ...
36
votes
3answers
88k views

Why does carbon monoxide have a greater affinity for hemoglobin than oxygen?

Hemoglobin is an iron-containing oxygen transport metalloprotein in the red blood cells of most mammals. Simply put, it's a carrier protein. Interestingly it doesn't carry carbon dioxide in the same ...
25
votes
9answers
6k views

What are oxidation states used for?

When I took high school chemistry many years ago, considerable effort was spent on teaching us to compute oxidation states of atoms in various compounds, following a set of rules that looked somewhat ...
24
votes
3answers
3k views

Is it possible for one specific atom in a molecule to have a non-integer oxidation state?

I am wondering if fractional oxidation states of an atom are possible. I'm not referring to cases such as $\ce{Fe3O4}$ or $\ce{Mn3O4}$ where the average oxidation state is fractional, since these ...
23
votes
1answer
934 views

What is the meaning of the “-osic” suffix on a metal (e.g., cobaltosic oxide)?

I just came across the term cobaltosic for the first time in the abstract of Ind Eng Chem Res 52(18): 6076, 2013 (emphasis added): A nanocomposite of cobaltosic oxide and nitrogen-doped graphene ($\...
22
votes
4answers
19k views

What should be the oxidation state of oxygen in HOF (hypofluorous acid)?

What should be the oxidation state of oxygen in $\ce{HOF}$ (hypofluorous acid)? Sources on the internet have confused me. Most state its oxidation state to be 0, while the others state that it is -2 (...
21
votes
1answer
1k views

Why does tin form tin (II) compounds?

The stability of the +II oxidation state in lead has been widely attributed to the so-called “inert pair effect”: the 6s subshell is stabilized through relativistic contraction due to the near-c speed ...
19
votes
6answers
5k views

Do atoms form either a positive or a negative charge, but not both?

I do not mean at the same time, of course, but I mean it appears from an overview of the common charges formed from ionizing various elements that each element forms one or more of either positive or ...
19
votes
1answer
1k views

An introduction to “oxidation state”/“oxidation number”

I just can't get my head around oxidation states. They're really confusing! Why do I need to assign a number to some element? What are oxidation states? How and why should we assign oxidation states? ...
17
votes
3answers
31k views

Oxidation state of the sulfur atoms in the thiosulfate Ion

What are the oxidation states of the two inequivalent sulfur atoms of the $\ce{S2O3^{2-}}$ molecule? For all I know is that Lewis Structure does matter in most of the cases.
16
votes
2answers
5k views

Electronegativity Considerations in Assigning Oxidation States

I have never seen anything other than a set of rules like these when textbooks present how to assign oxidation numbers. Such as these: However, if we keep in mind that oxidation numbers are simply ...
16
votes
1answer
720 views

What is the oxidation state of Mn in HMn(CO)5?

What is the oxidation state of $\ce{Mn}$ in $\ce{HMn(CO)5}$? If $\ce{H}$ has an oxidation state of $+1$, then $\ce{Mn}$ should have oxidation state of $-1$, which I'm not sure is possible. On the ...
16
votes
1answer
17k views

Why can Cu have an oxidation number of +2?

The electronic configuration for $\ce{Cu}$, adjusted for Hund's rule, is: $[\ce{Ar}] 3d^{10} 4s^1$ So, shouldn't $\ce{Cu}$ have an oxidation number of $+1$? whereby it gives off its outermost 4s ...
15
votes
1answer
715 views

Plutonium having more oxidation states than samarium?

Why does plutonium have more oxidation states than samarium? Electron configuration of Pu: $\ce{[Rn] 5f^6 7s^2}$ Electron configuration of Sm: $\ce{[Xe] 4f^6 6s^2}$ I thought that only the valence ...
15
votes
1answer
2k views

What is the nature of the Fe–O2 binding in oxymyoglobin and oxyhemoglobin?

Deoxymyoglobin ($\ce{Mb}$) is known to have iron in the +2 oxidation state; I believe this was deduced from its magnetic moment, which corresponds to four unpaired electrons in high-spin $\mathrm{d^6}$...
13
votes
2answers
723 views

Negative oxidation states of Si

According to List of oxidation states of the elements, silicon has a possible oxidation state of $-4$. Now, I've been looking everywhere for a compound that contains Si(-IV), but I cannot find any ...
12
votes
2answers
5k views

Does fluorine in FNO3 have +1 oxidation number?

According to my textbook and also Wikipedia, fluorine nitrate is a compound which can be created (though it is unstable). Also my textbook says that fluorine has a $+1$ oxidation state. But how is $+1$...
12
votes
1answer
1k views

Why are inert gas (especially Xenon) compounds powerful oxidizing agents?

I am curious as to why compounds with inert gases, such as $\ce{XeF4}$, $\ce{XeF2}$, and $\ce{XeO3}$ are considered powerful oxidizing agents. I would attribute the phenomenon to the highly oxidized ...
11
votes
1answer
3k views

Why is electronegativity increasing with oxidation state increase?

I may be a rudimentary fact or something really "not-that-hard-to-figure-out", but In inorganic chemistry it is common to consider a single value of the electronegativity to be valid for most "...
11
votes
1answer
101 views

Would cerium(III) in solution be oxidized to cerium(IV) in ESI mass spectroscopy?

During ESI (assuming positive ion mode for now), we apply a strong voltage ($1.0{-}\pu{5.0 kV}$) to induce ionization. Therefore, it is common to see oxidation of metal ions (e.g. $\ce{Cu^{+I} -> ...
10
votes
3answers
2k views

Oxidation state of fluorine in HOF

What should be the oxidation state of $\ce{F}$ in $\ce{HOF}$. As fluorine is the most electronegative element in the periodic table, it should be $-1$. But when I googled it, I found that many ...
10
votes
1answer
4k views

What allows sulfur and phosphorus to expand their octet?

There are many compounds in which the stability of a molecule is not governed by the presence of octet configuration in central atom. In most of the cases the central atom is generally sulfur or ...
10
votes
1answer
10k views

How to balance more complex redox reactions?

I'm in an advanced level chemistry course, and so far we've been introduced to balancing redox reactions. The basic ones like $$\ce{MnO4- + Cl- -> Mn^2+ + Cl2}\tag1$$ are pretty easy for me, but ...
9
votes
2answers
3k views

Why do single elements in a molecule have an oxidation state of zero?

For example, take $\ce{O2}$. The oxidation state of oxygen is -2, yet once its in a molecule its oxidation state becomes zero? How is this so?
9
votes
2answers
160 views

Are such high oxidation states as reported by Vojovodic et al. possible?

I am a student in theoretical chemistry and I am confused about the paper: Trends in adsorption of electrocatalytic water splitting intermediates on cubic $\ce{ABO3}$ oxides (Montoya, J. H.; Doyle, A. ...
8
votes
4answers
782 views

How is it possible to obtain a value of 8/3 as an oxidation state?

Iron's oxidation state in $\ce{Fe3O4}$. I really can't get the logic behind this.
8
votes
2answers
344 views

How to determine peroxy oxygen?

Which of the following compound doesn't contain peroxy oxygen? $\ce{CrO5}$ $\ce{Cr2O3}$ $\ce{Na2O2}$ $\ce{BaO2}$ I think peroxy oxygen is peroxide, am I right?. I have read in this ...
8
votes
2answers
4k views

Can lead(II) oxidize tin metal in aqueous solution?

According to my textbook, element $\ce{X}$ can oxidize element $\ce{Y}$ if $\ce{X}$ was lower in the activity series. Lead is lower than Tin in the activity series table in the textbook, but the ...
8
votes
2answers
506 views

Oxidation state of hydrogen in the LaNi5H intermetallic

This question is from an introductory chemistry course: What is the oxidation state of $\ce{H}$ in $\ce{NaH}$, $\ce{HCl}$, and $\ce{LaNi5H}$? I've looked in the textbook to no avail. Google ...
8
votes
2answers
1k views

Oxidation state of tungsten in W3O8

Recently I came across this equation: $$\ce{WO_3 +SnCl_2 +HCl\rightarrow W_3O_8 + H_2SnCl_6 +H_2O}$$ The compound $\ce{W_3O_8}$ that appears in the right hand side of the equation seems to be mixed ...
8
votes
1answer
319 views

Why don't we see these lanthanide species?

For most lanthanide metals$^{[1]}$, the stable oxidation state is III. The general electronic structure$^{[2]}$ is $$\ce{[Xe] 4f^{0}^{-14} 5s^2 5p^6 5d^{0}^{-1} 6s^2}.$$ Elements that have the d-...
8
votes
1answer
199 views

The oxidation state of iodine in iodoxybenzoic acid

I am slightly puzzled by this seemingly trivial question. The idea behind assigning oxidation states is simply to treat every single bond made by the atoms as ionic bonds. That is to say, both the ...
7
votes
2answers
35k views

Oxidation number for nitrogen in ammonium sulfate [duplicate]

I'm trying to find the oxidation number of $ \ce N$ in $ \ce{(NH4)2SO4}$. The answer is supposed to be $-3$ but I can't figure out the logic behind this.
7
votes
1answer
280 views

Is it possible for halogens to show oxidation states less than -1?

Halogens like $\ce{Cl,Br,I}$ generally show oxidation states between $-1$ and $+7$. However, is it possible that they can show an oxidation state beyond $-1$ (e.g. $-3$)? I was thinking of some ...
7
votes
3answers
9k views

Oxidation number of phosphorus in phosphine

Electronegativity of $\ce{H}$ is greater than $\ce{P}$, but according to my book in $\ce{PH3}$, $\ce{P}$ has oxidation number of -3. How is it possible? Is any of the data wrong?
7
votes
1answer
94 views

Reference for electronegativities of different metal oxidation states

A long time ago I was researching the effect of the self regulatory response in Fe and Co. I found that my results made sense based on the idea of the electronegativity of the ions considered. I found ...
6
votes
2answers
8k views

What is the oxidation state of sulphur in sulphur dioxide?

So for $\ce{SO2}$, here's the solution when finding for the oxidation number of sulfur. $$x + 2(-2) = 0 \\ x - 4 = 0 \\ x = +4$$ $x$ here would be the oxidation number of sulfur, so the compound ...
6
votes
1answer
3k views

How is the triferric tetroxide of iron possible?

If oxygen has a valency of $-2$, $4$ of it would result in $-8$. But iron doesn't have a (variable) valency of anything that goes to $-8$. Then how is $\ce{Fe3O4}$ possible?
6
votes
1answer
972 views

Why don't ligands affect the oxidation state of the central metal ion?

If $\ce{Fe^3+}$ were complexed with 6 $\ce{H2O}$ ligands, the resulting complex ion would be $\ce{[Fe(H2O)6]^3+}$, and the central metal ion would still have the same oxidation state of +3 as it did ...
6
votes
1answer
125 views

Is it possible for the iodine atom in periodate ester to be octavalent?

Recently, I was reading Clayden's Organic Chemistry (2nd ed.) and I chanced upon this diagram on p. 443 (as shown below) showing an octavalent iodine in the periodate ester. I found this rather ...
6
votes
1answer
443 views

Oxidation states of iron in Roussin's salts

For preservation of meat, sodium nitrite is usually added and as a result $\ce{NO}$ is then formed. Consequently, $\ce{NO}$ reacts with the sulfur and iron atoms from decomposition of proteins, ...
6
votes
1answer
3k views

Why are multiple oxidation states useful for a catalyst?

Transition elements are good catalysts because they have multiple oxidation states?Why multiple oxidation states matter?
6
votes
2answers
4k views

Propanoic acid reaction with potassium permanganate

I was conducting a lab where we have to identify/justify how functional groups affect the oxidation of a molecule. I used propene, propanone, and propanoic acid for this reaction. From what I have ...
5
votes
4answers
11k views

Are fractional oxidation states possible?

To get the oxidation state of carbon (denoted $x$) in octane, $\ce{C8H18}$, I used the fact that hydrogen has an oxidation state of $+1$: $$8x + 18\cdot 1 = 0 \qquad \Longrightarrow \qquad x = -\frac{...
5
votes
4answers
6k views

Why is MnO2 not a peroxide?

As I know, $\ce{MnO2}$ is called manganese(IV) oxide. Why can't we name it manganese peroxide since manganese(II) exists too? In other words, how do we know that the oxidation number of manganese in ...
5
votes
2answers
27k views

Why is NH2 negatively charged?

Whenever I look up the Lewis structure for $\ce{NH2^-}$, it shows 8 electrons. Now I understand the octet rule, but I still don't see how an electron can just appear from nowhere. There are 5 valence ...
5
votes
1answer
3k views

Oxidation state of nitrogen in triazirine (HN3)

The book asks me to find the oxidation state of nitrogen in the below compound: To find the oxidation state using Lewis structure, I have to compare the electronegativity of the bonded atoms and ...
5
votes
1answer
207 views

Typesetting oxidation state and charge simultaneously

I'm currently trying to typeset the ion $\ce{Cr2O7^{2-}}$ with oxidation numbers on. My first thought was to put the oxidation state above the atom, but according to IUPAC, the oxidation state should ...
5
votes
4answers
745 views

Which is more reactive, chlorine radical or chloride ion?

Ions are very reactive for obvious reasons (i.e. Coulomb force); $\ce{Cl-}$ ions will be very quick to form an ionic bond with positive ions (unless inhibited, e.g. through being in a solution; let's ...
5
votes
2answers
218 views

How to compare the bond lengths of an peroxide complex before and after oxidation?

The complex $\ce{K6[(CN)5Co-O-O-Co(CN)5]}$ is oxidised by bromine into $\ce{K5[(CN)5Co-O-O-Co(CN)5]}$. In this we have to comment on the change on length of $\ce{O–O}$. But for that we have to ...