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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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How to determine the greatest d orbital splitting?

This question comes specifically from an IB Chemistry HL Paper 1 in May 2018 TZ1, namely question 8. Which complex has the greatest d orbital splitting? It gives 4 Complexes $\ce{[Fe(H_2O)_6]^{2+}}$,...
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2answers
66 views

Why is phosphorus (v) oxides molecular formula P4O10 and not P2O5

I understand that the name derives from the empirical formula; however, I do not understand why it does not exist as $\ce{P2O5}$. Is there a compound that exists with this as its molecular formula?
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1answer
55 views

Unusual oxidation states of alkali metals

When going through list of oxidation states on Wikipedia I encounterd there that sodium, potassium, rubidium and caesium exhibit oxidation states of -1, but not lithium, even though its ...
3
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1answer
227 views

Why BiCl5 isn't stable?

I read this in a textbook: $\ce{Bi(V)}$ is very unstable and is a good oxidizing agent. Why does it happen that way? Is it because in $\pu{+5}$ oxidation state $\ce{Bi}$ pulls in more electrons ...
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1answer
76 views

What is the oxidation state of bromine in BrO3?

I came across this compound $\ce{BrO3}$ in my textbook, and was trying to find the oxidation state of bromine. This is how I proceeded: Since this is not a superoxide or a peroxide, or any other ...
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2answers
39 views

Is the reaction involving a proton transfer a redox reaction?

$$ \begin{align} \ce{H2S (aq) + NH3 (aq) &→ NH4+ (aq) + HS- (aq)}\tag{1}\\ \ce{Pb(s) + 2 FeCl3 (aq) &→ 2FeCl2 (aq) + PbCl2 (aq)}\tag{2} \end{align} $$ Which of the following statements ...
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77 views

Oxidation states of boron

I have just been looking at https://en.wikipedia.org/wiki/List_of_oxidation_states_of_the_elements and found that boron has a -5 oxidation state. I would like to know which boron compounds form ...
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1answer
32 views

Identifying if reaction is reduction or oxidation. Is there an error in this question?

I am looking at this reaction: I am trying to determine if it is reduction or oxidation. In the initial molecule I calculate the overall oxidation numbers as: ...
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1answer
35 views

Can superoxide ion act as a ligand in a similar fashion as peroxide?

There is a question in my chemistry book: Find oxidation state of platinum ion in the complex $\ce{[Pt(O2)(en)2Br]+}$. My books says that there is peroxide, but I want to ask why it is peroxide? ...
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0answers
57 views

Pale blue species forming during electrolysis of NaHCO3

I have a solution of 3500 ml $\ce{H2O}$ + 454 g $\ce{NaHCO3}$ in electrolysis at a potential of 12.5V using a lead anode and copper cathode. The surface areas aren't measured but they are enormous. I ...
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27 views

Comparing the number of oxidation states of Vanadium and Arsenic

USNCO 2004 Question 45 states: Which element exhibits the greatest number of oxidation states in its compounds? (A) Ca (B) V (C) Cu (D) As I ruled out Ca, as I know it only exists as +2. I ...
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Oxidation state of Mn in MnO₄⁻

I have tried to understand what the oxidation state for Mn in $\ce{MnO4^-}$ is. So far i have understood that O have the oxidation state of -2 so because there is 4 O the number turns to -8. What ...
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4answers
178 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 ...
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1answer
78 views

Oxidation states for covalent compounds [duplicate]

Yesterday, I came across $\ce{SO2}$ and was supposed to write the reduction and oxidation half reactions. However, I do not understand the reason why S is assigned the oxidation number of 4+. Oxygen ...
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54 views

Oxidation state of N in NO from resonance

I know from a textbook that nitrogen has an oxidation state of +II in NO, and this is easily verified if O is assigned -II. However, if one looks at the resonance structure and assigns covalent ...
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1answer
50 views

My confusion regarding Hydrogen peroxide

In Hydrogen peroxide, the oxidation number of oxygen is "-1" instead of "-2". But it seems to me that, the oxygen atoms have '-2' as their oxidation number as each oxygen atom here is connected to a ...
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1answer
276 views

Oxidation No. of Fe and NO in Nitroprusside ion [duplicate]

For the complex $\ce{[Fe(CN)5NO]^{2-}}$ wikipedia cites that the oxidation no. of Fe is +2 and that of NO is +1. CN being -1 the net charge thus becomes -2. However at certain places I read that NO is ...
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2answers
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Materials used in cooktop heating element, and reason for black appearance

I have been interested in the structure of heating elements/coils used in cooktops. I am referring to something such as in the following picture: I have a cooktop at home with such elements, and at ...
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1answer
120 views

Stability of 3d metal fluorides and iodides in different oxidation states

I read that the fluorides of 3d metals in lower oxidation states, e.g. $\ce{VF2}$, $\ce{TiF2}$, and $\ce{CuF}$ are thermodynamically unstable. For example, $\ce{CuF}$ disproportionates to $\ce{Cu + ...
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1answer
95 views

How to predict ease of oxidation or reduction for a given oxidising or reducing agent? [closed]

I have never understood which agent will be able to oxidize or reduce which type of reactants and yield which type of products will be formed. For example I want to know about DIBAL-H and how is it ...
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2answers
146 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. ...
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0answers
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What are the oxidation states of galium and arsenic in GaAs semiconductor?

According to the book I'm referring to ("S.M. Sze Semiconductor Devices"), gallium has an oxidation state of +1 and arsenic has that of -1. This should not be possible as each of these elements forms ...
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0answers
42 views

Why is this redox reaction possible?

I have the redox reaction $\ce{N_2H_4 {(g)} + N_2O_4 {(g)} -> N_2 {(g)} + H_2O {(g)}}$. In $\ce{N_2O_4 {(g)}}$, the oxidation state of nitrogen is $+4$. In $\ce{N_2 {(g)}}$, the oxidation state of ...
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0answers
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Effect of oxidation state on d-orbital splitting

I am trying to understand the effect of oxidation state on d-orbital splitting e.g. in Iron. I understand that splitting itself is caused by the fact that different d-orbitals are positioned ...
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2answers
58 views

Why is it a reduction from a ketone to an alcohol? [closed]

Why is it a reduction from a ketone to an alcohol (using $\ce{LiAlH4}$)? I'm not able to figure out the oxidation state of carbon.
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1answer
308 views

Why is the oxidation state of Co -1 in [Co(CO)4]-?

In $\ce{[Co2(CO)8]}$, most people say the charge of $\ce{Co}$ is 0. How does it become $\ce{[Co(CO)4]-}$? Most answers would say that $\ce{Co}$'s charge becomes -1. How does this work? -1 is not ...
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0answers
58 views

Is Potassium/Sodium Iodate a good oxidizer?

I've recently got a small batch of Potassium Iodate, Sodium Iodate and Sodium Nitrite each. I have seen that Nitrates, nitrites and chlorates are good oxidizers in pyrotechnics. But unfortunately ...
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1answer
245 views

Why does iron lose exactly 3 electrons in oxidation?

I'm not a chemist, but I have this question. Why does iron (Fe atom) lose three electrons when exposed to oxygen for the first time? Why doesn't it lose less than or more than three electrons?
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1answer
410 views

Why is oxidation number of Ba not +2 in this case? [closed]

According to redox rules, column 2 elements (alkali earth metals) have an oxidation number of +2, but in this reaction: $\ce{Ba + Cl2 -> BaCl2}$, the oxidation number of $\ce{Ba}$ changes from $0$ ...
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1answer
31 views

How does something like elemental oxygen oxidize anything if each atom's valence shell is full? [duplicate]

Been learning in biology about $\ce{O2}$'s role as an oxidizing agent, but I don't really understand how $\ce{O2}$ can take electrons from anything if it's not reactive....
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1answer
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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 ...
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2answers
1k views

Why oxides with the element in higher oxidation state are more acidic

We see this trend of acidic-basic property of oxides in most cases: $\ce{Mn2O7}$ is acidic, $\ce{MnO}$ is basic, the intermediate oxides are progressively less acidic and more basic, as the oxidation ...
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1answer
58 views

Prevent/Slow down oxidation of organic material

I'm having the hobby to draw paintings with the tea I drink trough the day. Usually I pour a tablespoon of the hot tea away, wait until it dries and gets more concentrated, so the colour is more ...
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1answer
127 views

Can Cl(g) cause quick rusting? [closed]

I'm actually digging in something that comes from Syria... How does Chlorine cause metal to get rusted? It's full of pictures of rockets (allegedly filled with chlorine gas) that are all rusted. In my ...
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1answer
263 views

Is the reaction of SiC and H2O a redox reaction?

In the reaction: $$\ce{SiC + 2H2O <=> SiO2 + CH4}$$ The oxidation state of Si is +4 in both SiC and SiO2, while the oxidation state of carbon is -4 in both SiC and CH4 (confirmed by this). Here ...
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1answer
517 views

Why do disproportionation reactions take place?

I want to know what are the conditions when disproportionation reaction is feasible. Is it just because of stability factors or it has other dimensions to it. As an example: $$\ce{3HNO2 -> HNO3 + ...
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1answer
283 views

Bond strength of pi acceptors and metals with filled d(pi) orbitals

I was reading in The Organometallic Chemistry of the Transition Metals (Robert Crabtree) that lewis acids like BF3 often accept electrons from d(pi) orbitals. Is this generally true for all pi ...
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2answers
558 views

In the blue bottle experiment, will it eventually be “used up” after repeated use?

The blue bottle experiment is a bottle half full of a colorless solution (dextrose, KOH, and methylene blue, in the version that I saw) and air that, when shaken, turns blue through the methylene blue ...
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1answer
83 views

Dumb Question about Oxidation

This is probably a really dumb question, but I can't find a clearly spelled out for me yes or no answer by searching through google, so hopefully I'll get a yes or no answer her. Can metals, for ...
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0answers
678 views

How do I balance the reaction equation of zinc and nitric acid?

How would you balance the following reaction using the oxidation number method? $$\ce{Zn + HNO3 -> Zn(NO3)2 + NH4NO3 + H2O}$$ My approach: Half reactions: \begin{align} \ce{Zn &-> Zn(NO3)2}...
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0answers
126 views

Ionizing radiation and oxidation without oxidizing agents

My knowledge on this subject is a bit rusty, so excuse me if I'm asking the wrong question here. I was taking a look at my high school chemistry books from many years ago, and I noticed that reduction ...
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1answer
770 views

Can nitrate and sulfate ions be oxidised during electrolysis of their molten compounds?

$$\begin{align} \ce{O2 + 4H+ + 4e- \;&<=> 2H2O}\quad\quad &&E^\circ = +1.229\ \mathrm{V}\\ \ce{S2O8^2- + 2e- \;&<=> 2SO4^2-}\quad\quad &&E^\circ = +2.01\ \mathrm{V} ...
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1answer
348 views

Decomposition of AsH3

In German problems olympiad 2014, the solution says that decomposition of arsine is not a redox reaction. Why would that be? Shouldn't H turn from -1 to 0 and As from 3+ to 0? $$\ce{2AsH3 -> 2As + ...
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Would cerium(III) in solution be oxidized to cerium(IV) in ESI mass spectroscopy?

During ESI (assuming positve 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} -> ...
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1answer
462 views

Identifying a Positive or Neutral Ligand Inside Coordination Sphere?

There are some coordination compounds like $\ce{Na2[Fe(CN)5NO]}$, where ligands like $\ce{NO}$ are used which exist as both $\ce{NO+}$ (nitrosonium ion) and $\ce{NO^.}$ (neutral nitrosyl). How to ...
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2answers
11k views

Why oxidation number of oxygen in OF2(oxygen difluoride) is +2? [duplicate]

I mean oxygen is electronegative element it should have negative oxidation number Also how it is able to make bond with fluorine which itself is electronegative? Why the oxidation number of oxygen ...
6
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1answer
642 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 ...
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1answer
549 views

Oxidation States of Actinides [closed]

It is observed that actinides do not exhibit +2 oxidation state, contrary to that of some of the lanthanide elements. Why?
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2answers
1k views

Can a solution of FeCl2 go bad over time?

My lab has been using solution of FeCl2 for an assay that was mixed about three years ago. Recently the assay has failed twice. I was wondering if it is possible that the iron ions in the solutions ...
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0answers
2k views

Why is lead (IV) chloride covalent while lead (II) chloride ionic?

I would like to find out more about what makes a compound ionic and what makes one covalent. However, I felt this was too general a question so I thought that asking about the chlorides of lead would ...