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 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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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Why does copper(II) sulfate or iron(III) nitrate work as a catalyst for the iodate variant of the Iodine Clock?
In the iodine clock reaction (iodate variation), the reaction of iodate and bisulfite ions apparently is the rate-determining step. I was wondering if $\ce{Cu^2+}$ and $\ce{Fe^3+}$ will act as ...
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Why isn't the n factor/valency factor in a disproportionation reaction = twice the number of electrons in a single half reaction? [closed]
I was reading the first answer to Equivalent weight in case of disproportionation reaction there it is said
Take a disproportionation reaction:- $\ce{nA -> xB + $(n - x)$C}$ where A is being ...
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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?
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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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what does the oxidation/reduction potential actually mean? [closed]
The standard potential of a species is actually its tendency to gain/lose electrons and get reduced/oxidized. But what I want to understand : 1- Is the standard potential an absolute quantity, or a ...
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What are disadvantages of methane or ammonia compared to dihydrogen for metal ore reduction?
Metallurgy, such as steel-making processes, require reducing agents to get rid of the oxygen in metal ores. Using fossil coal for this is a large source of $\ce{CO2}$ globally. Recently, I have read a ...
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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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What is the meaning of "maximum" weight produced after series ot reactions?
$4.14$ grams of a piece of lead was made to react with $\ce{HNO3}$ so as to produce lead nitrate. Lead nitrate further reacts with a series of reagents to form $\ce{(NH4)2PbCl6}$. Then find the ...
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Regarding the standard reduction potential and electrolyte/solid interface
I am modelling lithium-sulfur batteries ($\ce{LiS}$ batteries) and a strange phenomenom happens during charge, named infinite charging, which I show below:
The factor $f_\mathrm{C}$ that appears in ...
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EM Induction from Diffusing Ionic Wave Front
I am studying the Belousov-Zhabotinsky Reaction-Diffusion system in ~1mm wide 1-dimensional channels. In my research we are activating the reduced phase with a silver wire and studying the propagation ...
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What are some efficient approaches for balancing long chemical equations? [closed]
I am having some difficulties in balancing chemical equations involving many elements. It takes a lot of time (for me) to balance the coefficients using the hit and trial method. Especially like this ...
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Why does increasing the surface area of the cathode submerged in the electrolyte increase the current in a galvanic cell? [duplicate]
I can understand why increasing the surface area of the anode would increase the current, because the rate of oxidation will be increased resulting in a greater rate of flow of electrons through the ...
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Why can sulfate be oxidized to peroxodisulfate?
I am currently in high school and have encountered the following reaction in my course on electrochemistry:
$$\ce{2 SO4- -> S2O8^2- + 2 e-}$$
Why this reaction happens in the first place? Isn’t the ...
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Must a strong reducing agent be a weak oxidising agent, and vice versa?
As titled, must a strong reducing agent be a weak oxidising agent, and must a strong oxidising agent be a weak reducing agent? For instance, fluorine is a very strong oxidising agent, and it cannot ...
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Positive and negative voltage readings of chemical cells
In the experiment of chemical cells, I connected a magnesium electrode , a copper electrode and a multimeter in a complete circuit.
When magnesium electrode is connected to the negative terminal and ...
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How does sodium react with methanol?
Strong acids of $\ce{AH}$ type readily dissociate to its constituent ions (considering the solvent is water): $\ce{A-}$ and $\ce{H+}$. But the mechanism of the reaction between sodium metal and ...
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Why doesn't copper react with nitrate salts?
Copper reacts with nitric acid according to this equation:
$$\ce{Cu + 4 HNO3 -> Cu(NO3)2 + 2 NO2 + 2 H2O}$$
This is a redox reaction with copper getting oxidized, and nitrogen getting reduced. ...
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When HI reacts with H2SO4, why is the sulphate ion reduced to hydrogen sulphide instead of sulfur dioxide?
When $\ce{HI}$ reacts with $\ce{H2SO4}$, it can be represented by the following chemical equation:
$$\ce{8HI + H2SO4 -> 4I2 + H2S + 4H2O}$$
However, when $\ce{HBr}$ reacts with $\ce{H2SO4}$, the ...
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Question about reaction in battery
I made a battery like this.
$\ce{(-)Al|HCl,CuSO4|Cu(+)}$
By piling up 6 battery of this(actually I made this using 10 yen and 1 yen coins:10yen coin is Cu and 1 yen coin is Al.) I could turn on an LED ...
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