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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Role of MnSO4 in permanganometric titration
This might sound like a stupid question, but I have been unable to wrap my head around it.
Recently in a lab I had to titrate H2C2O4 with KMnO4 in acidic medium (H2SO4). However, in the work, it ...
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What is brown/red precipitate in battery acid
I am working on recovering some lead acid batteries that have lost some of their capacity. I drained all of the sulfuric acid out and there was an awful lot of brownish red precipitate in it. My ...
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Why does the reaction "pause" when the battery is not connected to a circuit? (or does it?)
The general set up, In an alkaline battery, the negative electrode is zinc (Zn) and the positive electrode is manganese dioxide ($\ce{MnO2}$). The alkaline electrolyte of potassium hydroxide (KOH)
At ...
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Why doesn't strong oxidising agent oxidises secondary alcohols to ketone in glucose?
Why sec. alcohols are not oxidized to ketones even though HNO3 is used as an oxidizing agent?
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Replacement for Centrifuge in Calcium Content Determination
Basically, I'm performing a lab investigation to determine calcium content in different milk sorts. Since my school didn't have any EDTA, I'm using Sodium Oxalate to form a precipitate with Calcium ...
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What is meant by 'as Cl2'
I feel like I'm over thinking this one, but think I need a confirmation (and quantified example) to put my confusion to bed. I'm more a mechanical than chemical background but trying my best.
I really ...
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How do I explain that voltage decreases when increasing the concentration of the cathode in a voltaic cell?
I just finished a lab experiment in which I built a voltaic cell with copper (II) sulphate and zinc sulphate. My experiment was to identify the correlation between the concentration of copper (II) ...
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When forming an epoxide with m-CPBA, what happens when we wash our mixture with Na2S2O4?
The m-CPBA is reduced by the $\ce{S2O4^{2-}}$, but why does it leave the mixture then?
Why does the reduced m-CPBA leave with the oxidised $\ce{S2O4^{2-}}$?
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is alkyl halide turning into alkene reduction or oxidation? [closed]
Is the reaction of 2-iodobutane turning into but-2-ene reduction or oxidation reaction?
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Acid dissociation constant from conductometric data
$\ce{0.007 M}$ aq. solution of anilinium hydrochloride had molar conductivity equal to $\pu{119.4 S cm2 mol-1}$, which became $\pu{103 S cm2 mol-1}$ when a few drops of aniline were added to 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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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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Which of the following might turn NaNO2 into N2? [closed]
Which of the following might turn $\ce{NaNO2}$ into $\ce{N2}$?
A. $\ce{NaCl}$ B. $\ce{NH4Cl}$ C. $\ce{HNO3}$ D. $\ce{H2SO4}$
The answer is B and we have
$$\ce{NH4Cl + NaNO2 = NaCl + 2H2O + N2↑}.\tag1$...
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Br- and I- ions give layer test, but Cl- ion doesn't. Why? [closed]
In a paragraph about "non-metal displacement", my book talks about chlorine displacing bromide and iodide ions in an aqueous solution. This results in the evolution of bromine/iodine gas ...
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What causes ionisation in redox reactions?
I'm trying to understand what's behind the ionisation of atoms in a redox reaction. I apologise if the answer to this question is obvious. I've searched around, but, surprisingly, I haven't found a ...
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Why does hypophosphorous acid oxidation occur in acidic media?
When one mole of $\ce{H3PO2}$ is treated with excess $\ce{I2}$ in acidic solution, one mole of $\ce{I2}$ is reduced; on making the solution alkaline, a second mole of $\ce{I2}$ is consumed.
I am ...
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Reduction of di-N-substituted imidazole to imidazoline to remove counterion?
I would like to synthesize a di-N-substituted imidazole (compound 4) in its free base form or reduce it to generate an imidazoline (compound 5) to remove the bromide counterion to the imidazole ring.
...
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What is the difference between combination reaction and addition reaction [closed]
In my textbook,two definitions were given separately
Combination: Two or more substances react to form one product.
Addition: Something is added to a chemical substance without elemination.
What is ...
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Breakdown of butyl rubber
I'm in my high school's theatre crew and of course we build a lot of props and such. However I just opened (yesterday) an old drawer of screwdrivers and they smelled like puke! I know that the ...
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Redox titrations : Oxidation of metallic Iron by Potassium Dichromate
0.31 g of an alloy of Fe + Cu was dissolved in excess of dilute $\ce{H2SO4}$ and the solution was made upto 100 ml. 20 ml of this solution required 3 ml of $\frac{N}{10} \ce{K2Cr2}\ce{O7}$ solution ...
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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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Why can't Al3+ be reduced to solid, pure aluminum?
There are efforts underway to develop ionic liquids for the purpose of reducing bauxite using exotic intermediates such as aluminum fluoride. However, the aqueous $\ce{Al^3+}$ ion is tantalizingly ...
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Why iron reacts with steam to give Fe3O4 not Fe2O3? [duplicate]
Why $\ce{Fe}$ with $\ce{H2O}$ gives $\ce{Fe3O4}$ not $\ce{Fe2O3}$?
Like, $\ce{Zn + H2O \rightarrow ZnO + H2}$, why $\ce{Fe}$ doesn't simply gives $\ce{Fe2O3}$ when it reacts with steam?
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What is happening in experiment coating a copper coin with zinc and turning it to brass?
Today in class we did the "gold penny" experiment, where we put metallic zinc and a penny in a zinc chloride $\pu{1 M}$ solution at $\pu{100 °C}$, which caused the penny to turn silver as ...
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Where does the ionisation energy for a reaction to take place comes from? [closed]
Can anyone tell me exactly what happens during a chemical reaction in terms of ionisation energy? I know that during a reaction there is an exchange of electrons (except for those where electrons are ...
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Electrode potentials at interfaces?
My questions relates to the fundamental concept of electrochemistry, more specifically the electrode potentials.
1) First, why is there a potential difference at the interface of two phases? ...
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Chloramines & Nitrogen Trichloride vs Stainless Steel [closed]
We've recently experienced excessive corrosion on stainless steel within indoor pool environments. We believe this is due to chloramine (gasses) in the atmosphere. To test this, I plan to create a ...
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Why does metal atom get an effective potential difference in voltaic cells [closed]
Why is it that metal atoms , experience this potential difference when immersed only in their salt solutions. When they are in contact in real life we cannot see current conducting through it.
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Hydrogen fuel cell - why do the H+ ions move through the electrolyte
Consider the following hydrogen fuel cell
http://butane.chem.uiuc.edu/pshapley/Enlist/Labs/FuelCellLab/FuelCell.html
At the anode, hydrogen is oxidised (losing electrons). My first question is this: ...
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Weight Ratio vs Molar Ratio - Chloramines
I'm working with a delicate experiment whilst trying to test corrosion of stainless-steels in a chloramine environment. I've run into various literature that discusses the formation of different types ...
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Sodium borohydride and lithium aluminium hydride
Both sodium borohydride and lithium aluminium hydride are common reducing agents in organic chemistry. Then can these reducing agents be applied in inorganic chemistry? I mean, for example, reducing ...
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Balancing the Redox reaction by Half reactions
I'm having trouble balancing this reaction using half reactions:
$$\ce{I2 + KOH -> KI + KIO3 + H2O}$$
I so far know that iodine is reduced when it forms $\ce{KI}$ (oxidation noumber decreases from ...
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Formation of hypofluorite from F2 and hydroxide
Why $\ce{FO-}$ can't form in reaction of $\ce{F2}$ with $\ce{OH-}$ but $\ce{ClO-}$ can form on reacting $\ce{Cl2}$ with $\ce{OH-}$?
Is $\ce{FO-}$ very unstable?
I know that fluorine can't have ...
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In which medium is Potassium Permanganate a better oxidising agent?
I was in chemistry class just now, and my chemistry teacher gave us three reactions:
Reaction 1: $\ce{MnO4^- + e- -> + MnO4^2- (basic medium)}$
Reaction 2: $\ce{MnO4^- + 4H+ + 3e- -> + MnO2 + ...
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Reduction of La(NO3)3 to La(NO2)3
I'm writing a master's thesis on some lanthanide compounds, in particular those with $\ce{Ce^{+3}}$ and $\ce{La^{+3}}$, although my focus has now shifted to lanthanum, but I ran into a problem when I ...
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Does 50% hydrogen peroxide dissolve gold?
We have seen that the silver electrodes on a piezo element are being seemingly dissolved by exposure to our mixture of $50\,\%$ hydrogen peroxide. I was wondering if we were to switch to gold ...
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Why is sodium zincate two sodium ions and two oxygen ions but only one zinc ion? [closed]
$2$NaOH + Zn ---> Na2ZnO2+H2
I have always been fascinated by this reaction because it never made sense to me why sodium zincate has such a strange composition. Why does it have two sodium and ...
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Lithium aluminium hydride
Lithium aluminium hydride is an important reducing agent in organic chemistry.
Since I cannot find the half-equations telling how this reducing agent performs its action, I am wondering, is lithium a ...
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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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What gives dilute/conc nitric acid/ conc sulfuric acid their oxidizing property?
I know that dilute sulfuric acid and very dilute nitric acid don't have any oxidizing tendency while dilute/conc $\ce{HNO3}$ and conc $\ce{H2SO4}$ do.
Why do these more concentrated acids have this ...
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What is the effect of temperature on titration between Iron(II) sulfate and potassium permanganate
I'm conducting an experiment in school, the titration of Iron(II) sulfate dissolved in H2SO4 against potassium permanganate. In this, I am varying the temperature that the analyte is heated to and ...
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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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Can this equation be balanced using ion-electron method?
Reaction:
$\ce{C2H4 + O2 → CO2 + H2O}$
I want to balance the above reaction using the ion-electron method.
My attempt:
Ox-half: $\ce{C2^(^-^2^)H4 + 4H2O → 2C^(^+^4^)O2 + 12H^+ +12e^-}$
Red-half: $\ce{...
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Can all equations be balanced using ion-electron method?
Consider the reaction of a mixture of $\ce{C2H4}$ and $\ce{CH4}$ with $\ce{O2}$. Using the hit-and-trial method, this is the balanced chemical reaction:
$\ce{C2H4 + CH4 + 5 O2 -> 3 CO2 + 4 H2O}$
...
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What is the purpose of the solution in a galvanic cell?
In other words: What is the purpose of the solution that the electrodes are immersed in, in a galvanic cell, and is it possible to generate a current without any solution?
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How does a silver chloride electrode (Ag/AgCl) convert the potential in aqueous solution to the wire?
I am aware of the redox chemistry that happens at the electrode surface, but I'm not sure how exactly a change in electrical potential in the solution would change the potential in the electrode?
CommunityBot
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How to reduce Fe(III) impurity in Iron(II) sulfate?
I have bought 50 kg $\ce{FeSO4}$, but it was stored on air, and it has turned to brown. Is there a cheap method to recover some $\ce{FeSO4}$?
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Is it possible for a surplus of electrons to be generated during a chemical reaction? [closed]
I was wondering whether a chemical reaction can produce excess electrons after the completion of the reaction, in addition to generating by-products (chemical compounds) and heat.
In other words, can ...
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Can someone explain why there is OH in the Standard Reduction Potentials Table
$$\ce{SO4^2− + H2O(l) + 2e− <=> SO3^2− + 2OH−}$$
This is the half-reaction that I am having trouble understand.
I have read online that OH- is used to cancel out the protons(H+) in basic ...
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What (stored-as-solids) acids/liquids can clean corroded copper?
I'm looking for a liquid that can remove copper corrosion (oxides and basic carbonates - the black and green stuff) off copper piping.
The corrosion will be located on the inside of the pipe, in hard-...
