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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Aromatisation of Alkanes
My textbook mentions the following reactions:
However the mechanism is not available
What is the mechanism for cyclisation and aromatisation of an n-alkane and how does the catalyst help?
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Help me solving the formula of the experiment determing the level of COD [closed]
The formula I'm using is this:
COD(mg/L or ppm) = (b-a) * 1000/V * 0.2
a : 0.025N KMnO4 standard solution consumed in the baseline test (ml)
b : 0.025N KMNO4 consumed in titration (ml)
V : Volume of ...
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Why Cu(s) + 4HNO3(aq) → Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) reaction really occurs? [closed]
I want to know why exactly this reaction is occurring. In my understanding, metals have different reactivity and Hydrogen is more active than Copper. So I thought Copper can't replace Hydrogen. I read ...
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Glycation of peptides (Maillard reaction) by reductive amination
I would like to link glucose to the primary amines in a peptide containing lysine. Can I just mix glucose and the peptide and add some cyanoborohydride to perform a reductive amination? As long as my ...
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Finding cell potential in disproportionation reactions - a clarification regarding the value of n
Consider the following half cells.
$$Cu^{+} + e^{-} \rightarrow Cu, E^o_{cell1} = 0.52 V…(1)$$
$$Cu^{2+} + e^{-} \rightarrow Cu^{+}, E^o_{cell2} = 0.16V…(2) $$
This gives us,
$$Cu^{2+} + 2e^{-} \...
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Oxygen tolerant RAFT polymerization using AIBN?
I want to do some RAFT polymerizations but don't have a nitrogen line at the moment. It seems that people have recently implemented oxygen scavenging strategies to enable open-air RAFT polymerization. ...
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Will charcoal (carbon) oxidize in the air?
Wikipedia — Carbon sequestration claims that burying charcoal into the soil offsets $\ce{CO2}$ and thus reduces the greenhouse effect:
In the soil, the biochar carbon is unavailable for oxidation to $...
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The edge case of an edge case: Vapor emissions of the descaling agent Sulfamic acid
I am wondering about the following scenario:
What happens if ready bought sulfamic acid descaling (usually 15% cont. + $\ce{H2O}$) is vaporized or at least steam develops while very briefly descaling ...
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Why is the theoretical value of the electrode potential different to the experimental value for Cu and Al for a galvanic cell by using Nernst equation
I've construct a galvanic cell with the Al strip putting in the Aluminum nitrate solution and Cu strip putting in the CuSO4 solution. KNO3 is used as the salt bridge in this experiment. The question ...
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How does KI catalyze the reaction with H2O2?
I've done a Google search regarding this question, and have found that there is no place online which answers this question to the degree that I want. Unfortunately, every site online stops at the ...
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Thiol vs carboxylic acid reactivity to acyl chlorides?
I want to form a thioester between some acyl chlorides and NBoc-cysteine. Is the free thiol so much more reactive than the carboxylic acid in cysteine that the side product formation of carboxylic ...
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Why didn't copper act as a reducing agent
In lab, we took $\ce{CuCl_2(aq)}$ and poured it into a cup. Then we took some aluminum foil and put it inside and started to stir. I could see the aluminum getting eaten by the copper because it was a ...
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How come in biuret test the copper sulfate doesn't react with the sodium hydroxide?
As I understand the color change in the biuret test is due to the formation of a complex between the peptide (with more than 2 peptide bonds) and the $\ce{Cu^2+}$ ion, from $\ce{CuSO4}$. But before ...
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What happens if an element has two different oxidation numbers on the same side of reaction?
I am taking General Chemistry 1 and I am studying redox reactions. I was looking at the following combustion reaction:
$$\ce{4CH3 + \underset{O: 0}{7 O2} \to \underset{O: -2}{4CO2} + \underset{O: -2}{...
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Can an oxidising/reducing agent oxidise/reduce itself? [closed]
I am new to the study of this divine science. So Just a query: Can an oxidising/reducing agent oxidise/reduce itself? If it can can anyone give an example and explain it?
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Which reaction is most likely to take place in a voltaic cell? [closed]
I was confused by this MCQ:
The answer is A. I thought that the spontaneous reaction was usually between the most negative and least negative. Could someone please explain why this is the answer.
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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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Why doesn't the Nernst Equation match my data at low values of Q?
I have formatted my data below in a table so my issue is more clear and asked this question again, I apologize for any confusion. I don't understand why the low values of Q are inaccurate while the ...
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Cell notation of all aqueous solutions
If some redox reaction happened with no solid anode or cathode, like all aqueous solutions, something like the unbalanced reaction
$$
\ce {MnO4^- (aq) + C2O4^-^2 (aq) -> Mn^+^2 + CO2 (aq)}
$$ What ...
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Why the change of the position of the salt bridge or metal piece leads to different voltage value?
I am doing an experiment where I use salt bridge to create galvanic cell. The goal of my experiment is to find if there is some correlation between the amount of solvent being used and the voltage ...
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Can pyruvate get reduced after glycolysis?
During cellular respiration, the first step is glycolysis where the glucose is split into 2 pyruvates, 2 NADH, and 2 ATP. The pyruvate either goes through the citric acid cycle or goes through lactic ...
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Concentration of solution when a battery reaches equilibrium
Problem: We want to build a battery employing as electrodes ${\text{PbSO}_4}_{(s)} | {\text{Pb}}_{(s)}\ (E^º=-0.351\ V)$ i ${\text{Cd}}_{(aq)}^{2+} | {\text{Cd}}_{(s)}\ (E^º=-0.4026\ V)$ in a solution ...
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Electrode potential and likeliness to reduce/oxidize (electrolysis) [closed]
I'm a little confused about situations where multiple chemical compounds can be reduced/oxidized and the likelihood of this happening to one compound over the others, depending on the electrode ...
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Why is water present in "pure" nitric acid and RFNA and WFNA?
Various types of nitric acid have been used in rocket fuels as oxidisers (RFNA is red fuming nitric acid, WFNA is white fuming nitric acid) as they are often hypergolic with a wide variety of fuels.
...
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Usage of acid in redox titration [closed]
I've came to know, diluted H2SO4 is used as medium in KMnO4 titration. Whereas, HNO3 is not used as it is an oxidizing agent. My question is H2SO4 is also an oxidizing agent. Then what's the problem ...
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battery using zinc, copper, and vinegar
I filed one side of a penny to reveal the zinc; then I bent the coin and dropped it into a cup of white vinegar. Shortly afterward, many tiny bubbles were forming on the zinc side. Later on, I noticed ...
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What form of energy is produced by 2H2 + O2 -> 2H2O reaction? [closed]
I'm curious about are the details of exothermic nature of 2H2 + O2 -> 2H2O reaction. The explanations I've seen just use a term "energy release" without specifying what type of energy it ...
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Why is there a discrepancy between predicted and nominal voltages of alkaline batteries?
According to Wikipedia, the sum of standard reduction potentials for the half reactions for alkaline battery yield $\pu{1.43 V}:$
$$\begin{align}
\ce{Zn(s) + 2 HO–(aq) &-> ZnO(s) + H2O(l) + 2 e–...
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Why does copper(II) sulfate react with potassium iodide in aqueous solution?
According to the list of standard reduction potentials [1, p. 5-79] $E^\circ(\ce{Cu^2+/Cu^+}) = \pu{+0.153 V},$ while $E^\circ(\ce{I2/I^-}) = \pu{+0.5355 V}.$ Doesn't it mean that iodine has more ...
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Redox titration, complex formation effect on lg'K?
We have performed the following redox titration
(1): $\ce{MnO_4^- + 8H^+ + 5Fe^2+ <=> Mn^2+ + 4H_2O + 5Fe^3+}$
where we have used a iron(II)solution (the analyte) and titrated it with a ...
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How to determine the cell potential of chromium(III) — permanganate cell?
Determine the cell potential of the following cell:
$$\ce{Pt | Cr^3+ (\pu{0.125 M}), Cr2O7^2- (\pu{0.200 M}), H+ (\pu{0.600 M}) || MnO4- (\pu{0.150 M}), Mn^2+ (\pu{0.400 M}), H+ (\pu{0.250 M}) | Pt}$$
...
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Confusion regarding what reduction/oxidation means in reactions having covalent compounds [closed]
In the formation of NaCl, Na gets oxidised because it loses an electron, while Cl gets reduced because it gains an electron.
But how does this concept work in the case of covalent compounds, ...
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Redox reactions: In order to get as much copper as possible from a reaction, one usually adds an excess of zinc. Why?
In order to get as much copper as possible from a reaction, one usually adds an excess of zinc. Why? We already have a set amount of zinc needed to reduce all the copper(II) ions. Why should we add an ...
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Cyclic voltammetry graph of graphite electrode in NaOH
I'm a student who is a beginner to cyclic voltammetry and university electrochemistry in general. For my lab experiment, I performed cyclic voltammetry on a graphite electrode in 1 M NaOH with Ag|AgCl ...
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NAD+ and NADH /H+
The $\ce{NAD^+}$ molecule has an electron-poor carbon susceptible to a nucleophilic attack by a hydride ion: It's the C4 of the pyridine ring, who loses its aromaticity in this way.
Usually, it is ...
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How to balance iodometric equations using ion electron method? [duplicate]
I found out the reductant, oxidant, oxidation half reaction, reduction half reaction; balanced ions (adding $\ce{H2O},$ $\ce{H+},$ electrons) and charges:
$$\ce{K\overset{-1}{I} + \overset{+2}{Cu}SO4 -...
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Reaction of lead with acetic acid and hydrogen peroxide solution
My textbook says lead reacts with acetic acid when there is enough oxygen to oxidize lead:
$$\ce{2 Pb + O2 + 4 CH3COOH -> 2 Pb(CH3COO)2 + 2 H2O}$$
So, I added lead into mixed solution of acetic ...
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The difference between Zn and Al on acid and base reaction
Because it was written on my textbook that Zn and Al dissolves in acid and alkali, I tried.
When I put Al in NaOH solution it reacted immediately. But when I put Zn in the same concentration of NaOH ...
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Why doesn't hydrochloric acid oxidize tin to tin(IV) chloride?
Diluted hydrochloric acid oxidizes tin to $\ce{Sn^2+}$ ion:
$$\ce{Sn + HCl(aq) -> SnCl2(aq) + H2(g)}$$
Why is oxidation not complete? $\ce{Sn^4+}$ has closed shell and is more stable.
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What do you think is happening to aluminium in salt water with rusted copper?
I put some aluminium foil and rusted copper(namely a Japanese 10 yen coin) in saturated NaCl solution.
After some minutes tiny amount of small bubbles were observed on the surface of the foil.
After ...
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Reaction of hydrogen peroxide with acetic acid and potassium permanganate
I conducted an experiment where I mixed hydrogen peroxide $\ce{H2O2}$, acetic acid $\ce{CH3COOH}$ and potassium permanganate $\ce{KMnO4}$ under vigorous stirring. The reaction hasn't stopped after 15 ...
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Conditions for Pd/C reduction of alkene
I am trying to do a $\ce{H2}$ reduction of cyclic alkene (otherwise simple hydrocarbon with 1 methyl group along with the chain about the weakly-strained cycle) using $\ce{Pd/C}$, the cycloalkene ...
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How does xenon react with O₂F₂?
This reaction was asked in my college entrance exam. I searched through the entire Internet, but I couldn't find any papers/sources.
I suspect since O₂F₂ is a strong fluorinating agent, one of the ...
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Stoichiometric coefficients in reaction between vanadium(II) oxide and iron(III) oxide
Calculate the weight of $\ce{V2O5}$ produced from $\pu{2g}$ of $\ce{VO}$ and $\pu{5.75 g}$ of $\ce{Fe2O3}$
Now we write the reaction as following - $$\ce{2 VO + 3Fe2O3-> V2O5 + 6FeO}$$
Now, by the ...
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Can you oxidize gold using only oxygen?
I keep reading that gold does not react with oxygen, but I also see information about gold Oxides (ie: aurous oxide, Au2O and auric oxide, Au2O3)
Knowing that there is a way of getting gold oxide ...
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Calculating half-cell potential from two reduction potentials [duplicate]
It is sometimes necessary to compute E° for a given half reaction from other half reaction of known E°.
For example, the standard electrode potential for the oxidation of Titanium metal to Ti³⁺ can be ...
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Mechanism of the blue bottle experiment
I have researched multiple mechanisms for this experiment yet all of them suggest different versions or are too vague. None of them are consistent since the final overall equation seems to be missing ...
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Reaction of copper(II) chloride and aluminium foil
So I did an experiment recently with copper(II) chloride and aluminum. As they reacted with each other the redox reaction made the aluminum a brown substance that is supposed to be copper and the ...
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What drives double displacement reactions?
I have two questions:
I understand that in a displacement reaction the more reactive element displace the less reactive element. But why? In the reaction with Zinc and Copper Sulfate, we form Copper ...
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Would this redox titration be possible as a direct titration rather than a pseudo-back titration?
In a general chemistry lab protocol (green chemistry, ISBN-13: 978-1482230208), students determine the content of ascorbic acid in a vitamin C tablet. There is an ascorbic acid standard in a buret, ...
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