Questions tagged [redox]

Redox is the portmanteau of reduction and oxidation. This tag should be used in questions where both the reduction and the oxidation process are under focus. This tag is not limited to inorganic chemistry. If the question is specifically about either reduction or oxidation (not both) of an organic compound, use [organic-reduction] or [organic-oxidation] instead.

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Products of electrolysis of Ni(NO3)2

During the electrolysis of $\ce{Ni(NO3)2}$ using nickel electrodes, it's said that the molarity of the solution remains constant as nickel's active, and dissolves and deposits in equal measure. But ...
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please answer this question instantly [closed]

Electrolysis of dilute H2SO4 produces H2 gas at cathode. If the minimum voltage required is 1.24V, how many joules of Energy will be used up to produce 1 kg of H2 gas?
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What is the first ionization energy of the hydride ion?

What is the first ionization energy for hydride? Since there are two electrons in the s orbital, I suppose it should be more stable than hydrogen, despite the extra electric charge, so the ionization ...
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Oxidation of Vitamin C

How is ascorbic acid oxidized into dehydroascorbic acid? What is the reduction reaction in this case? Where are the 2 hydrogen atoms going?
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In a battery, what happens to LiCoO2 when the lithium leaves? It becomes CoO2?

What chemical compound exists at the cathode of a lithium-ion battery when the lithium is not there? The cathode is usually described as $\ce{LiCoO2}$, so does it become $\ce{CoO2}$? $\ce{CoO2}$ ...
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Industrial production of alkali metals

My professor says that $\ce{Li}$ and $\ce{Na}$ are produced by electrolysis, while $\ce{K, Rb}$, and $\ce{Cs}$ are made via the reaction $\ce{Na + MCl -> NaCl + M}$, where $\ce{M = K, Cs, Rb}$. I ...
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Is the effect of hydroperoxyl radicals significant in the oxidation of organic compounds in the Fenton reaction? Why or why not?

In the Fenton reaction, a ferrous catalyst and hydrogen peroxide are used to generate hydroxyl radicals which in turn oxidise organic compounds. The reaction is commonly seen in the treatment of ...
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effective way to mitigate ocean acidification [closed]

Compare the effectiveness between the sea grasses plantation and the carbonate addition in maintaining the pH of the ocean slightly high.
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Why does nital need alcohol when etching metals?

I was reading about HNO3 and I saw it can be mixed with alcohol to form "nital", which is useful when etching metals, especially carbon steel. I wonder why alcohol is needed? HNO3 itself is ...
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Electrolysis of aqueous copper (II) nitrate

There are two copper blocks sitting in the $\ce{Cu(NO3)2 (aq)}$ solution, a battery is attached onto both of them, providing enough energy to start the reaction. Since solid pieces of copper are ...
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I have a doubt regarding redox reactions [duplicate]

Oxidation state of P in PH3 is? On drawing structure, it's very evident that P has single bonds with H and had one lone pair. Now as Electronegativity of P>H, shouldn't Hydrogen have -1 charge and ...
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Why do bubbles form when a reactive metal is placed in a less reactive metal's salt solution?

What is the gas that if formed when a reactive metal is placed in a salt solution of a less reactive metal? Theoretically, it should just be a simple displacement. I know that this question has been ...
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Does standard electrode potential depend upon temperature?

Does standard reduction potential depend on temperature? I am confused because my institute gives the definition for standard reduction potential as the potential that is measured at standard state ...
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I am having problem with this question including topics of redox reactions and charges [duplicate]

What is the oxidation number of $\ce{Fe}$ in $\ce{K4[Fe(CN)6]}$? This seems to be a pretty easy problem. Just input the oxidation numbers of everything and equate for 'x'. But the problem is that I ...
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In a galvanic cell, why do electrons move through the wire from zinc to copper?

I understand that there is aqueous $\ce{Cu^2+}$ in this scenario which pulls on the electrons from the zinc causing the electrons to move through the wire, but how does the electronegativity of $\ce{...
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How to calculate n factor for salts in this reaction?

My source says : For salts which react such that no atom undergoes change in oxidation state , n-factor for such salt is the total moles of cationic /anionic species replaced in 1 mole of the salt . ...
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What exactly is formed when K2Cr2O7 is reduced?

I read on Wikipedia and in many books that when $\ce{K2Cr2O7}$ is reduced, it forms $\ce{Cr^3+}$ and a change is noticed from orange color to green. I want to know in what exact complex/salt/compound $...
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Is HBrO2 a reductor?

I'm working on a chemistry project and that features a reaction where $\ce{Br-}$ participates in a redox reaction as a reductor. Eventually, $\ce{HBrO2}$ competes with $\ce{Br-}$ to react with the ...
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Can the 5+ and 4+ oxidation state of Vanadium ion exist independently?

From my class text book: The oxidation states of Vanadium ions 5+ and 4+ are shown in the compounds $\ce{VO2^{+}}$ and $\ce{VO^{2+}}$ respectively, whereas $\ce{V^{3+}}$ and $\ce{V^{2+}}$ are ...
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How does the charge imbalance affect the cell reaction when there is no salt bridge in a galvanic cell?

As mentioned in the answers to this question Why is it important to use a salt bridge in a voltaic cell? Can a wire be used? a salt bridge is used to keep the two half cells neutral. i understand how ...
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How does aluminium react with bases to form aluminates?

An example of reaction: $$\ce{2Al + 2KOH + 6H2O->2 K[Al(OH)4] + 3H2 ^}$$ Aluminium is not ionic, how then does it attract the $\ce{OH-}$ groups to bond with them into the complex ion $\ce{[Al(OH)...
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Rusting of iron is quicker in saline water than in ordinary water [duplicate]

I feel so because, saline water has more more electrons and because of that there will be oxidation will take place faster and hence the overall process will speed up. Is this explanation good enough ...
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How does sodium in ethanol reduce carbonyl compounds?

According to my teacher, Na in ethanol reduces carbonyl compounds (e.g. aldehydes and ketones) to alcohols. However, I can't see where the hydrogen needed for reduction comes from. How does the ...
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20 mg solid PbO2 is stirred at room temperature in 2 ml water for 10 minutes and filtered. Then KI is added [duplicate]

20 mg solid PbO2 is stirred at room temperature in 2 ml water for 10 minutes and filtered. What will happen if you treat the filtrate with aqueous KI solution? Mention the colour, state of the mixture ...
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Does NaOH react with K to form NaOK or KOH?

I realized that the $\ce{-OH}$ group when it reacts with some metal like $\ce{Na}$ or $\ce{K}$ will replace the $\ce{H}$ element to form $\ce{-OK}$ or $\ce{-ONa}$: \begin{align} \ce{H2O + Na &...
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m-CPBA Selectivity between Baeyer Villiger Oxidation and Epoxidation?

If both a ketone and an alkene are present in a molecule and you add one equivalent of m-CPBA, what are the factors that determine which group will be oxidized, the ketone through Baeyer-Villiger ...
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Is cyclic ether oxidised by periodic acid?

Is the three member ring of cyclic ether oxidised by periodic acid? As this also has oxygen attached to adjacent carbon so I think that cyclic ether of three members should be oxidised by periodic ...
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Br- and I- ions give layer test, but Cl- ion doesn't. Why? [closed]

One of the questions I found in an NCERT book. Interestingly I could not find the answer anywhere on the internet. Hence, stack exchange.
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Experimental measurment of thiosulphuric acid decomposition kinetics

Problem I am trying to do a kinetics analysis on the following reaction: $$\ce{Na2S2O3 {(aq)} + 2 HCl {(aq)} -> S {(s)} + 2 NaCl {(aq)} + SO2 {(g)} + H2O {(l)}}$$ Suggested Method However, most ...
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Balancing reactions algebraic method limitations [duplicate]

How do I balance this reaction using the algebraic method? Seems that the equation can't be solved. How do I balance such reaction and does the algebraic method has limitations and wont work for ...
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Balancing disproportionation reactions

How to balance the following disproportionation reaction $$\ce {XeF2 + H2O → Xe + XeO3 + HF + O2} $$ My attempt: I tried by making total number of reductions equal to total number of oxidation but ...
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Confusion about the oxidation state of copper in copper cyanide re-dissolved with excess cyanide

$\ce{CuSO4}$ when reacts with $\ce{KCN}$ forms $\ce{CuCN}$ while it is insoluble in $\ce{H2O}$. It is soluble in excess of $\ce{KCN}$ due to the formation of the following complex: a) $\ce{K2[Cu(CN)4]}...
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Is reduction of copper oxide a combustion reaction?

Is the following reaction a combustion reaction or just a single displacement? Could be both? $$\ce{H2 + CuO -> Cu + H2O}$$ A friend of mine claims it is a combustion reaction because it is ...
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Reaction between halogens and concentrated nitric acid

I have read that the reaction between $\ce{I2}$ and conc. $\ce{HNO3}$ gives $\ce{HIO3}$ and $\ce{NO2},$ but there is no mention of the other halogens' products. Do they all give halous acids and ...
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Does Br2/H2O oxidize all aldehydes including carbohydrates?

In many books, it is mentioned that aldehydes are easily oxidized even by mild oxidizing agents. However, I have never seen bromine water explicitly mentioned. But in the carbohydrates chapter, it is ...
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439 views

What is the reaction between nitric acid and fluorine?

Nitric acid, $\ce{HNO3}$, is a strong oxidising agent as well as fluorine, $\ce{F2}$. What will be the reaction when pure $\ce{F2}$ gas is bubbled through 100% pure $\ce{HNO3}$. While searching, many ...
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What is the state of aggregation of iodine formed during electrolysis of molten nickel(II) iodide? [closed]

Assume the electrolysis of molten $\ce{NiI2(l)}$ (inert electrodes) in a cell. The cell with a heating element is in the room; the room is at $\pu{25 °C}$ and $\pu{101.3 kPa}.$ The half-reaction for ...
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Why is chromate stable in basic medium and dichromate stable in acidic medium?

When I was studying the equilibrium existing between chromate and dichromate ions in the solution, I came to know that Chromate ion is more stable in basic medium while dichromate ion is stable in ...
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1answer
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Which is a dye: Ferric Acetate or Ferrous Acetate?

I’ve been trying to make Iron Acetate to dye leather and I cannot, for the life of me, figure this out experimentally. I’ve been allowing steel wool to react with pure white vinegar in a sealed glass ...
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How to know dichromate is being reduced from Cr⁶⁺ to Cr³⁺?

When potassium dichromate is being used as an oxidising agent, it gets reduced from chromium(VI) to chromium(III). Is there any way to know that or calculate that other than being familiar with ...
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Balancing a redox equation with only one product

Is it possible to balance this equation using the half reaction method? $$\ce{Au + Cl2 + HCl⟶HAuCl4}$$ I know that the equation balanced would be: $$\ce{2Au + 3Cl2 + 2HCl⟶2HAuCl4}$$ However, how ...
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1answer
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Explaining the colour change in the potassium permanganate titration of iron(II) ions

In the redox titration: $$\ce{MnO4- + 8 H+ + 5 Fe^2+ -> Mn^2+ + 4 H2O + 5 Fe^3+}$$ the colour change which occurs is purple to colourless, because of the decreased concentration of permanganate ...
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In acid/base chemistry, are there amphoteric substances that undergo something that resembles disproportionation in redox chemistry

Some substances disproportionate. This means a species with an intermediate oxidation state yields two species with higher and lower oxidation state. For example: $$\ce{Hg2Cl2 -> Hg + HgCl2}$$ My ...
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Effect of charge density on electrolysis of dilute sulphuric acid

I am told that if electrolysis of dilute sulfuric acid is performed under high charge density, then the following reaction takes place at anode instead of evolving oxygen: $$\ce{2 HSO4- -> H2S2O8 +...
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Can aqua regia work with sources of chloride and nitrate other than hydrochloric acid and nitric acid?

According to Professor Poliakov and a question on Chemistry Stackexchange here, gold dissolves in aqua regia because the nitrate ion oxidizes the gold into $\ce{Au^3+}$, and the chloride bonds to the ...
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Possible methods for copper (II) reduction to copper (I)

How can I make $\ce{Cu2O}$ from copper? I am seeing if electrolysis is a good route (in the context of kitchen style chemistry) to cuprous oxide, instead of the traditional heating copper and ...
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Why does sodium react with water?

The reaction of sodium with water is quite infamous. $\ce{2Na + 2H_2O \rightarrow 2NaOH + H_2}$ But exactly why does $\ce{Na}$ displace $\ce H$ in $\ce{H_2O}$?
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How is it determined how many electrons are transferred in redox reactions?

For example, iron and tin(II) sulfate will react to produce iron(II) sulfate and tin: $\ce{Fe + SnSO4 -> FeSO4 + Sn}$ With the following half equations: $\ce{Fe + SO4^{2-} -> FeSO4 + 2e-}$ ...
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Are there acid/base processes in aqueous solution that are so slow that they are kinetically controlled?

This question came up in figuring out what the fundamental differences are between redox chemistry and acid/base chemistry (if any). In redox chemistry, strong oxidants and strong reductants can co-...
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Understanding sodium hydroxide drain cleaner's exothermic dissolution of aluminum; does the aluminum need to be oxidized before it dissolves?

I'm not a chemist but I remember that the standard HF/nitric silicon etch used in micro-fabrication supposedly worked in two steps; the HF would dissolve the thin SiO2 oxide layer on the silicon ...

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