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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Electrochemistry: Voltage, solution resistance, current/m3 & designing a supply to maintain perameters
As it would seem current density is affected by several factors. Electrode Ae, electrolyte concentration, electrolyte conductivity, etc..
I'm conducting a series of experiments involving the ...
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26 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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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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3answers
46 views
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
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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
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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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26 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 ...
2
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1answer
42 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
78 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
85 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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What is the oxidation number of (S4O6)^2-? [duplicate]
When I am doing a redox reaction concerning $\ce{S_2O_3}^{2-}$ being oxidized into $\ce{S_4O_6}^{-2}$ . I found out that the oxidation number of $S$ in $\ce{S_4O_6}^{2-}$ is $2.5$ . Doesn't ...
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1answer
83 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
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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
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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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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
55 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
208 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
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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
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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
295 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
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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
862 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
53 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
98 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
217 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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0answers
432 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
224 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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Oxidation of Fe to Fe3+ (corrosion)
Why does $\ce{Fe}$ get oxidized directly to $\ce{Fe^3+}$ if $\ce{O2}$ is present, but only to $\ce{Fe^2+}$ if oxygen is not present?
I've tried comparing the half reactions:
\begin{align}
\ce{Fe &...
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2answers
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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
78 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
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When performing an experiment looking at the effect of pH, will titration as a method of analysis change the pH during analysis?
I am designing an experiment looking at the effect kf pH on the oxidation state of Fe ions. Basically, I will be dissolving ferrous sulphate in different concentrations of sulfuric acid (0.1M-5M), ...
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532 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}$$
My approach:
Half reactions:
\begin{align}
\ce{Zn &-> Zn(NO3)2}...
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0answers
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Ionizing radiation and oxidation without oxidizing agents
My knowledge on this subject is a bit rusty, so excuse me if I'm asking the wrong question here. I was taking a look at my high school chemistry books from many years ago, and I noticed that reduction ...
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1answer
665 views
Can nitrate and sulfate ions be oxidised during electrolysis of their molten compounds?
$$\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
281 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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0answers
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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
373 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
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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 ...
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1answer
532 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
478 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
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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
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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 ...
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0answers
85 views
Confusion about Sodium Nitroprusside [duplicate]
In Sodium Nitroprusside and related compounds (eg. brown ring complex) why is the oxidation state of NO +1 and not zero? It seems pretty unusual without any explanation.
Could anyone please explain ...
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0answers
300 views
What defines the oxidizing/reducing power of a coordination compound?
For example, I came across a problem in which I was asked to determine whether the complex $\ce{[Cr(H2O)6]Cl2}$ is an oxidizing or reducing agent.
How should I proceed? My teacher told me its the ...
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1answer
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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}$...
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1answer
64 views
Why is oxygen oxidized with lead instead of being reduced?
Oxygen is more electro negative yet in the redox reaction
$$\ce{2PbO(s) -> 2Pb(s) + O2(g)}$$
my text book says lead is reduced and oxygen is oxidized. How can this be? It doesn't make sense to ...
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1answer
2k views
Does cold bluing steel prevent rust?
I've recently purchased a Damascus knife and am patiently awaiting it's arrival in the mail. I have been researching the potential care and maintenance habits for this craftsman blade, hoping to keep ...
