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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 ...

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What should be the reaction between lead oxide and dilute sulfuric acid?

I know for a fact that dilute $\ce{H2SO4}$ is a non-oxidizing acid which makes it a reducing agent. I also know for a fact that $\ce{PbO2}$ is a strong oxidizing agent. So, I thought Redox reaction ...
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22 views

Why heating up things before H2C2O4 &KMnO4 titration? [closed]

In my school, there is a redox titration between H2C2O4 being titrand and KMnO4 being titrant. After adding H2SO4 to the acid to give an acidic medium for redox, the whole mixture inside the conical ...
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24 views

What substance consumes oxygen from atmospheric air [closed]

I'd like to find an economical substance that will consume oxygen from a container. Steel wool comes to mind but I don't have an intuition how feasible it would be. The chamber is 5 gallons in size ...
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What is the electrode potential at the equivalence point if concentrations of titrant and titrand are going to be zero?

Let's assume that the titrand is $\ce{Fe^2+}$ and the titrant is $\ce{Cr2O7^2-}$. Then $$E = E^\circ_\ce{Fe^{2+}/Fe^{3+}} - \frac{RT}{nF}\ln\frac{\ce{[Fe^{2+}]}}{\ce{[Fe^{3+}]}}$$ $$E = E^\circ_\ce{...
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How do you determine the oxidation state change on a transition metal ion when it is exposed to a strong oxidizer or reducer?

According to this sheet, metal ions will go from their -ous to their -ic state when they are in the presence of an oxidizer, and from their -ic to -ous state when in the presence of a reducer. ...
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1answer
19 views

Can all oxidizing agents be used interchangeably in organic chemistry reactions? [closed]

Butanol can be oxidized with pyridinium chlorochromate (PCC) yielding butanal. If the case is that butanol can be oxidized with PCC, can it be oxidized with CrO3, H2SO4, HNO3, OsO4, and other ...
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39 views

Does hydrogen peroxide in basic medium only give oxygen gas on oxidation?

Does hydrogen peroxide on oxidation gives oxygen gas only in basic medium? I thought that was true but I read about these reaction of $\ce{H2O2}$ in acidic medium: $$\ce{2MnO4- + 6H+ + 5H2O2 -> ...
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25 views

What is the purpose of hydrogen gas in a zinc-hydrogen electrochemical cell?

I understand that in a metal-gas electrochemical cell there is what is known as the gas electrode. At the gas electrode, an inert substance is used to provide a surface on which say a reduction half ...
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1answer
58 views

Why can't sulphate ion be discharged in the anode of electrolysis?

Given that there is an aqueous solution of sulfuric acid ($\ce{H2SO4}$), $\ce{2H+}$ is reduced in the cathode and $\ce{OH-}$ is reduced in the anode. Why is $\ce{OH-}$ preferentially discharged over $\...
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23 views

What drives the redox reactions in a standard hydrogen electrode?

In this video, the SHE half cell has two redox reactions occurring i.e. $$\ce{2H+ (g) + 2e- <=> H2 (g)}\\ \ce{H2 (g) <=> 2H+ (g) + 2e-}$$ But how can a single half cell initiate the two ...
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What is the strongest oxidising agent? [closed]

I searched for the strongest oxidising agent and I found different results: $\ce{ClF3}$, $\ce{HArF}$, $\ce{F2}$ were among them. Many said $\ce{ClF3}$ is the most powerful as it oxidises everything, ...
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1answer
74 views

The reaction of iron with sulfur to produce Iron(II) sulfide is inconvenient (for me)

I am taking a lot of iron properties this semester, but I have found some contradicting piece of information about the reaction of iron with nonmetals illustrated with two cases \begin{align}\ce{ **...
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1answer
67 views

Balancing the reaction of nitric acid with zinc using oxidation number method

In a previous question, there was confusion relating to what this "oxidation number method" is. So I will illustrate that before my question. Write the skeleton equation representing chemical ...
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58 views

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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19 views

Can catecholamines be quantified by HPLC-MS/MS at high pH?

It seems that most HPLC-MS/MS methods used for quantitation of catecholamines (epinephrine, norepinephrine and dopamine, specifically) operate at low pH (commonly 3.0), and therefore demand the ...
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2answers
147 views

What is reduced and oxidized when potassium bromate reacts to oxygen and postassium bromide?

I'm trying to help lead my daughter to a solution and my high school chemistry is almost 30 years ago. For the following reaction, indicate the species being oxidezed and reduced and show the ...
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1answer
137 views

Balancing using oxidation number method

Balance the following equation using oxidation number method: $\ce{PbS + H2O2 -> PbSO4 + H2O}$ Attempt: I have written down the oxidation states of all atoms and we can observe reduction of ...
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0answers
76 views

Why add NaBH4 slowly to 4-t-butylcyclohexanone in ether solution? [Lab Procedure]

$\ce{NaBH4}$ is to be added slowly to 4-t-butylcyclcohexanone in ether solution according to laboratory procedures, but I am curious as to why that is? 4-t-butylcyclohexanone undergoes reduction with $...
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1answer
65 views

Not sure why, but I can't modify/balance this equation

I'm working on modeling a few reactions for my research. For example: $$\ce{CO2 + H2S + CH4 <=> CH3SH + H2O}$$ was one I grabbed from the literature. However, this reaction is taking place in ...
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1answer
54 views

Balancing the intermolecular redox reaction

The redox reaction is: $\ce{SO2 + Na2CrO4 + H2SO4 -> Na2SO4 + Cr2(SO4)3 + H2O}$ This is what I tried(tho I got stuck at one point which is indeed the exact reason why I've asked this question): ...
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2answers
65 views

Reduction of hydrogen sulfide by silver

Why can $\ce{H2S}$ be reduced by $\ce{Ag}$ when left in air: $$\ce{2 Ag + H2S -> Ag2S + H2}$$ If silver is a noble metal that should not reduce hydrogen?
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When can colourimetry be used to determine the rate of reaction?

Can colourimetry be used if a coloured reactant react to give a coloured product? For example, in the reaction of reacting dichromate ions with oxalate ions in acidic environment, where dichormate ...
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1answer
137 views

Reaction of solid silver sulfide on warming with dilute nitric acid

Solid silver sulfide is warmed with dilute nitric acid. I thought that the nitric acid would engage with silver sulfide in a double displacement reaction, as follows: $\ce{Ag_2S {(s)} + 2H+ {(aq)} -&...
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39 views

Why do we need iodometry?

In case of iodometry where we need to find the concentration of an oxidant, we react it with $\ce{I^-}$ and check how much $\ce{I_2}$ is produced. Then we use a reducing agent with known volume & ...
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39 views

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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1answer
109 views

Does chlorine trifluoride react with candlewax?

I've run across references to chlorine trifluoride quite a lot. It pops up fairly regularly on the Worldbuilding SE, and whatever idea people have with it is usually shot down very quickly - For ...
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1answer
75 views

Maximum possible hypochlorite concentration from electrolysis?

For reference, "electrochlorination" is just the electrolysis of a simple solution of water and table salt (NaCl) followed by reintroducing the chlorine gas produced. But, the Wikipedia article on "...
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1answer
59 views

Why is the conjugate of a strong oxidizing agent a weak reducing agent?

I am a grade 12 student. While I was reviewing some electrochemistry, I had the following question. Take this reduction half-reaction: $$\ce{F2 (g) + 2e- <=> 2F- (aq) + $\pu{2.87V}$}$$ I know ...
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44 views

Balancing Redox reaction : with 2 species being oxidized [closed]

I have a redox reaction I found from a chemistry book from the 1970's. Two chemical species are oxidized, the Chromium and Iodine. $\ce{CrI3 + KOH + Cl2 -> K2CrO4 + KIO4 +KCl + H2O}$ Hope someone ...
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68 views

Safely lowering bleach pH without chlorine gas?

According to Eurekalert, by lowering the pH of household bleach (e.g., by adding vinegar or citric acid), we can increase $\text{[HOCl]}$ and consequently greatly improve the disinfecting capabilites ...
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44 views

Galvanic Corrosion in a Galvanic cell

I am doing an individual practical at school, which requires us to investigate the reactivity of metals, using galvanic cells. My initial proposal was to investigate the effectivity of different metal ...
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1answer
118 views

Why is ascorbic acid (vitamin c) readily oxidised in the presence of oxygen?

I know that vitamin c is notoriously unstable in aerobic conditions, but I'm not sure how to explain why it is - is it due to redox potential, acid strength etc?
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How to balance redox reactions possessing oxidation number change in multiple elements? [duplicate]

Hello, I am bit confused about balancing these type of redox reactions where multiple elements are involved in oxidation and reduction reactions. If I try to use half reaction ion exchange method and ...
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41 views

Methionine/Cysteine under redox control [closed]

Methionine and cysteine are the principal sulfur-containing amino acids, and oxidation of cysteine and methionine residues had been well studied. How come NOT all proteins carry Methionine and/or ...
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1answer
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Identifying Donation of an Electron Pair

Which one of the following reactions does not involve the donation of an electron pair? A) $\ce{H+ + CH3NH2 -> CH3NH3+}$ B) $\ce{AlCl3 + Cl- -> AlCl4-}$ C) $\ce{CH3Cl + CN- -> CH3CN + Cl-}$...
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53 views

Why does acidic medium accelerate rusting?

When learning about the corrosion of iron, I was teached that the following half-reactions happen: $$ \ce{Fe -> Fe^2+ + 2e- } $$ $$ \ce{2H2O + O2 + 4e- -> 4HO-} $$ First question is: do these ...
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73 views

What is the reaction of ammonium nitrate with hypochlorous acid [closed]

What would the product of ammonium nitrate and hypochlorous acid? Would there be any reaction? Would the HOCl get broken down? Trying to determine if the free chlorine content would be diminished upon ...
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1answer
114 views

What is the purpose of the electrolyte in the half-cell where oxidation is taking place?

In an electrochemical cell that consists of two half-cells, there is an electrolyte and an electrode in each half-cell. Example: $$ \begin{align} \ce{CuSO4(aq) + 2e- &-> Cu(s) + SO4^2-(aq)} \\ ...
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45 views

Is the ionic solution of a half-cell part of the electrode in a electrochemical cell? [closed]

A simple electrochemical cell consists of two half-cells, that is: a metal solid submerged in a solution. Additionally, there is salt bridge connecting the half-cells. Ex: $\ce{Cu(s)}$ in $\ce{CuSO4(...
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1answer
27 views

Why aqueous KI is used when collecting Iodine?

In room temperature solid di-iodine pentoxide($I_2O_5$) reacts with carbon monoside to form carbon dioxide & Iodine. This can be used to measure the amount of carbon monoxide in an air sample. $...
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56 views

The halide ions as reducing agents

So I'm currently an A-level student, and we learnt at some point last year that iodide ions were (at least compared to the halides above it) strong reducing agents - strong enough such that if sodium ...
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2answers
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Predicting products of chemical equations? [duplicate]

Consider the equation $\ce{2 NaOH (aq) +Cl2 (g) —> NaOCl (aq) + NaCl (aq) + H2O (l)}$. How would one know the products of this reaction? Is there a general way of doing this? I would have no ...
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Balancing the reaction of potassium permanganate and sulfuric acid with hydrogen peroxide [duplicate]

A problem on redox reactions invites the reader to balance the actual reaction from which the redox simplification arose. After some hunting I found the balanced equation and attempted to re-derive ...
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2answers
38 views

Zinc and copper salt bridge replacement [closed]

If I were to replace $\ce{Zn}$ with $\ce{Al}$ in $\ce{Zn|Zn^2+ || Cu^2+|Cu}$. Would it produce the same results?
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1answer
67 views

Which is a better oxidising agent: concentrated nitric acid or dilute nitric acid?

I was reading the Wikipedia page on nitric acid and saw the reaction of concentrated $\ce{HNO_3}$ and dilute $\ce{HNO_3}$ with $\ce{Cu}$. It is mentioned that: Copper reacts with dilute nitric ...
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25 views

Why is Co³⁺ such a strong oxidising agent? [duplicate]

The reduction potential of Co³⁺ is 1.81 suggesting the very strong oxidising nature of Co³⁺. I wanted to know the reason why is it so?
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Examples for oxidation of fluoride and for fluoride as a base

I have no university degree in chemistry and I’m curious about some examples - explained with the applicable rules (or the exception from the existing rules) - for the following statements (from this ...
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1answer
114 views

How does calcium chloride act as a sequestrant (food science)?

This Wikipedia page lists common sequestrants (with respect to food science). As stated on the page: A sequestrant forms chelate complexes with polyvalent metal ions, especially copper, iron and ...
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Why is fluorine the best oxidising agent, but also the most basic?

(Please note that all comparisons I have made below are with respect to halide ions only.) According to what I have learnt, the fluoride ion is the most basic ion, because it has the smallest size ...
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Can you ignite the thermite reaction in a solution?

As far as I know thermite is a typical redox reaction where $\ce{Al + Fe^{3+} -> Fe + Al^{3+}}$ happens. I guess the activation energy is very high, because you need to split the $\ce{Fe_2O_3}$ ...