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.
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Effect on Metal-Phosphine Bond if Metal centre gets oxidised
Looking at the Octahedral complex, the chromium is a $d^6$ complex and, if the Chromium bond gets oxidised, it will have lesser electrons to donate to phosphine's $\sigma^{*}$ orbital.
This effect is ...
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Find cell configuration notation for permanganate in acidic medium
They gave us an unbalanced reaction of permanganate and iodide in acidic medium, and ask to balance the reaction using redox methods and the write the cell configuration notation for the resultant ...
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Why does the 2+ oxidation state of Gold typically not occurr? [duplicate]
I'm currently researching a material containing gold in various oxidation states as part of my graduate school project. In the literature I found compounds where gold occurs in a 1+ and 3+ oxidation ...
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What is the oxidation state of atoms in interstitial transition compounds?
My teacher said that even though interstitial compounds are neither ionic nor covalent, we still define an oxidation state for them. The example she gave was $\ce{TiC}$. She said the carbon is in $-4$ ...
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Why does Ascorbic Acid on paper turn brown when heated?
I am finding conflicting information about how ascorbic acid degrades and turns brown when used as "invisible ink" on paper and then heated. Some say the heat accelerates the natural ...
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Can Sodium form Anions? [duplicate]
I am at the beginning of self-studying chemistry and one question I have is quite simple yet I can't seem to get an answer that people agree on, or I am not searching for it properly.
The question is ...
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Oxidation Number of the middle carbon in $\ce{C3O2}$ (Carbon Suboxide)
By taking the oxidation state of the terminal oxygen atoms as -2, and oxidation state of the carbon atoms adjacent to these oxygen atoms as +2, we are left with the oxidation state of the middle ...
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Oxidizing property of permanganate [closed]
If permanganate is a stronger and efficient oxidizing agent in acidic medium than alkaline medium.
Then why does it oxidise iodide(-1) to iodate(+5) in alkaline medium but iodide to iodine(0) in ...
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When HI reacts with H2SO4, why is the sulphate ion reduced to hydrogen sulphide instead of sulfur dioxide?
When $\ce{HI}$ reacts with $\ce{H2SO4}$, it can be represented by the following chemical equation:
$$\ce{8HI + H2SO4 -> 4I2 + H2S + 4H2O}$$
However, when $\ce{HBr}$ reacts with $\ce{H2SO4}$, the ...
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Specifying which compound is oxidized/reduced in a redox reaction [closed]
I wrote the oxidation numbers in a redox reaction:
$\rm{2 \overset{+7}{Mn} \overset{-2}{O_4^{-}}~+~5\overset{+4}{S} \overset{-2}{O_2}~+~6\overset{+1}{H}_2 \overset{-2}{O}~~\rightarrow~~ 5\overset{+6}{...
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In a voltaic cell with standard hydrogen electrode is the measure half cell always the cathode?
I am a bit confused. My openstax textbook states:
"When the half-cell X is under standard-state conditions, its potential is the standard electrode potential, E°X. Since the definition of cell ...
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Can you write oxidation states with negative Roman numerals?
As I understand, Roman numerals are used for oxidation states, whereas Arabic numerals are used for the charge of full ions, with some ambiguity allowed when a metal centre is all but ionised, such as ...
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Make Yellow rust on cast iron
I am an artist looking for a chemist to collaborate with. I an trying to create Yellow Rust on an old french cast iron fireplace insert.
Aside from vinegar, salt and hydrogen peroxide (that result in ...
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Is valency of an element equal to sum of covalency and electrovalence? Why do we calculate valency and oxidation number? [closed]
About valency books say following things:
1- Valency is combining capacity of an atom with number of hydrogen atoms or double of oxygen atoms with which the atom combines.
Doubt A: what is valency of ...
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Confusion regarding what reduction/oxidation means in reactions having covalent compounds [closed]
In the formation of NaCl, Na gets oxidised because it loses an electron, while Cl gets reduced because it gains an electron.
But how does this concept work in the case of covalent compounds, ...
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Why middle elements of transition series show more number of oxidation states [duplicate]
Why do the elements in the middle of the transition series show more number of common oxidation states than others?
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Balancing a redox reaction equation with a mystery reactant
The answer to the following question from NSAA 2021 Chemistry Section 2 is C.
Consider the following chemical equation:
$$\ce{vQ + wP4 + x H2O -> yPH4I + zH3PO4}$$
where Q is a binary compound.
...
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Why Scandium (Sc) doesn't show variable oxidation states (especially +2), while other transition elements show variable oxidation states? [duplicate]
I have read answer to this question on various sites, but was not satisfied by the answers, because I am not able to understand, that if we remove initially 1 electron from scandium, then 4s would be ...
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Do polyatomic ions have oxidation numbers?
In a polyatomic ion, the sum of the oxidation numbers of all atoms is equal to the overall charge on the ion. However, does this polyatomic ion have an overall oxidation number?
We also know that the ...
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What are oxidation numbers of each element in CuH?
My chemistry teacher said hydrogen when bonded with metals has oxidation number (O.N.) of −1 except CuH: in CuH the hydrogen has O.N. +1 and the copper has O.N. −1.
But on the internet it is ...
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Why chlorate(V) is one of the primary products of disproportionation reaction between chlorine gas and hot concentrated NaOH?
Cold diluted $\ce{NaOH}$ reacts with $\ce{Cl2}$ producing hypochlorite:
$$\ce{2 NaOH(aq, dil, cold) + Cl2(g) -> NaClO(aq) + NaCl(aq) + H2O(l)},\tag{R1}$$
whereas hot concentrated $\ce{NaOH}$ yields ...
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How is 1 mole hypochlorite ion equivalent to 1 mole chlorine gas?
According to my book, 1 mole ClO- is equivalent to 1 mole Cl2. How is that even possible? 1 mole ClO- contains 1 mole Cl atoms. On the contrary, 1 mole Cl2 gas contains 2 mole Cl atoms. So, how are ...
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Is haloform reaction considered to be disproportionation? [duplicate]
A question in an exam listed a number of compounds and the task was to find the number of compounds which will undergo disproportionation in conc. $\ce{NaOH}$. One of the compounds was $\ce{CCl3CHO}$, ...
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Can halogens show -3 or -5 or -7 oxidation state. Why? [closed]
I mean can we think it like if the electrons get excited into the d orbitals and because there are now more than one unpaired electron, why does it only loose them and why don't they accept more than ...
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Does hypochlorous acid oxidize hydrogen peroxide?
The following reaction is from https://ncert.nic.in/textbook/pdf/kech202.pdf, p. 11:
$$\ce{H2O2 + HOCl -> H3O+ + Cl- + O2}$$
I have to find if $\ce{H2O2}$ is acting like a reducing agent or an ...
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Computing the overall charge of a compound with non-integer coefficients
I have a question about computing the overall charge of inorganic chemicals, where the composition is expressed using non-integer stoichiometric coefficients.
Let's say we have $\ce{Hg_{0.7}Cd_{0.3}Te}...
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Why doesn't XeF6 displace oxygen from water?
Consider the following reactions (unbalanced):
$$
\begin{align}
\ce{XeF2 + H2O &→ Xe + HF + O2} \tag{a} \\
\ce{XeF4 + H2O &→ XeO3 + Xe + O2 + HF} \tag{b} \\
\ce{XeF6 + H2O &→ XeO3 + HF} \...
user121185
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In Lanthanides, Why is electron removed from 4f before 5p? [duplicate]
I've been taught that electrons are removed first from valence shell electrons with highest energy. But In Lanthanides, for example taking configuration- [Xe]4f⁴6s², If we go to +3 Oxidation State, ...
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Balancing a chemical reaction with oxidation numbers
We have been teached how to balance chemical reactions with oxidation numbers in school, but somehow I can't understand it.
This is the equation to balance
$$\ce{Cu(s) + NO3−(aq) + H+(aq) -> Cu^2+(...
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In the complete combustion of methane, is it methane or carbon that is oxidised?
I realise this is a rather pedantic question, but I'm wondering which application of terminology is more correct here.
I know that, in the complete combustion of methane, methane is the reducing agent....
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Do molecules containing enough oxygen to burn themselves exist?
Is there a molecule with enough oxygen in it (for example, something like $\ce{HCOOOH}$) such that it can undergo complete combustion without requiring any additional oxygen? For example the above ...
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Will strong base corrode aluminium in absence of oxygen? [closed]
From what i understand, putting iron in a vacuum chamber (airtight container) will stops further oxidation take place.
However in aluminium, with only oxygen, aluminium will form thin oxide film that ...
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Why are group 13 compounds in the +1 oxidation state more ionic than those in the +3 oxidation state?
I know that for group 13 metals in the p block, the stability of +1 OS is generally more than the stability of +3 OS as it is energetically not favourable to attain the higher OS of +3 and such ions ...
user120098
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Oxidation of sulfuric acid to Marshall's acid and its half cell reaction
$\ce{H2O2}$ can be prepared by successive reactions:
$\ce{2NH4HSO4 -> H2 + (NH4)2S2O8}$
$\ce{(NH4)2S2O8 + 2H2O -> 2NH4HSO4 + H2O2}$
The first reaction is an electrolytic reaction and second is ...
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How can one change the color of Iron Oxide by changing the composition or hydration?
How does the color of rust change depending on its makeup and state, or more to the point, how would one put the rust into that state?
For example, Wikipedia shows Iron(III) Oxide as being red in the ...
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What are the safest non-toxic elements I can own? [closed]
As in a recent question, I mentioned I collect elements. My collection already has quite a few elements and a rare alloy
(I have silicon, molybdenum, tungsten, gold, platinum, silver, copper, ...
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Can osmium react with oxygen at room temperature?
I’m an avid collector of elements (I love shiny rocks - don’t judge).
I’m looking to buy some osmium, as it’s one of the heaviest and hardest metals out there.
However, people online told me to avoid ...
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Oxidation number of methylene blue
I came across methylene blue's structure when it reacts with oxygen.
The left is the reduced state, and the right is the oxidized state.
However, when I looked at them carefully, the oxidation number ...
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The oxidation number of N and Cl in NOClO4
My doubt is not about the solution itself, actually I was able to find the solution myself.
We could split NOClO4 as (NO+) + (ClO4-) and then proceed, but here I "knew" this split. Is there ...
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Is Co(2+) easily oxidised to Co(3+)? [closed]
I think this question lacks some required informations but that's exactly what was given on my question paper. I thought of explaining this in descriptions of crystal field theory but I couldn't solve ...
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What exactly is oxidation number with regards to [Fe(CN)6]-4 [closed]
I read that $\ce{Fe}$ has an oxidation state of $+2$ in $\ce{[Fe(CN)6]^{4-}}$. Does that mean $\ce{Fe}$ gives away $2$ electrons? Doesn't $\ce{(CN)6}$ form coordination bonds with $\ce{Fe}$ meaning $\...
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What are compounds where oxygen has oxidation state -1/3 called?
I have heard of oxides, peroxides and superoxides where oxygen oxidation number is $-2, -1, -\frac{1}{2}$ respectively.
But I came across a molecule with the formula $\ce{KO_3}$, oxygen has $-\frac{1}{...
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How do I balance a hydrogen peroxide redox equation? [closed]
I have this equation:
$$\ce{H2O2 + MnO4- + H+ -> O2 + Mn^2+ + H2O}.$$
How do I balance it, since O has two different oxidation states on one side?
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Why does mercury(II) nitrate form only when using concentrated nitric acid?
In the reaction between mercury and nitric acid, mercury(II) nitrate only forms when concentrated nitric acid is heated up and added to it, if the acid is dilute, mercury(I) nitrate forms.
I ...
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Why sodium metabisulphite is not an oxidising agent? [closed]
We know that the maximum possible oxidation state of sulphur is $+6$. Whereas the oxidation states of sulphur in sodium metabisulphite are $+3$ and $+5$. Can't these oxidation states reduces to a ...
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Does boron exhibit +1 oxidation state?
My teacher told that boron exhibits only a $+3$ oxidation state, but he also wrote the unbalanced reaction
$$\ce{B + C -> B4C}.$$
Carbon has greater electronegativity than boron leaving us with $\...
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Apparent inversion of oxidation state of sulfate ion using minimal basis set
It is well known that the sulfate ion has essentially no 3d-2p bonding; hence I used the minimal basis set(STO-3G) for the NBO calculation I did via Gaussian, just to check it.
However, I got a ...
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Balancing disproportionation reaction of hypoiodous acid
In aqueous solution, the acid $\ce{HIO}$ disproportionates according to the following equation where m, n, p and q are simple whole numbers in their lowest ratios.
$$\ce{mHIO → nI2 + pHIO3 + qH2O}$$
...
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How To Know Which Oxidation Number To Use For Nitrogen [duplicate]
When given a compound like (NH4)2MoO4 and asked to find the oxidation number of Mo, how do I know which oxidation number to sub in for Nitrogen? On the periodic table, Nitrogen has oxidation numbers ...
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Why does CO2 have a greater affinity for hemoglobin than oxygen?
I know about CO but I am wondering if CO2 has similar mechanism? do you guys have any scientific reference
These species help form interactions between amino-acid residues at the interfaces of the ...
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