Redox is the portmanteau of reduction and oxidation and therefore refers to reactions in which electrons are transferred and in consequence the oxidation state of the involved elements changes.

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Dissolving metal reductions

Could reduction of an organic compound by reacting it with sodium dissolved in $\ce{NH3}$ still proceed if a metal such as aluminium were used instead of sodium? I'm not sure about the aluminium amine ...
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Disproportionation with aqueous NaOH

Which of the following undergoes disproportionation with $\ce{NaOH}$? $\ce{SiO2}$ $\ce{CO2}$ $\ce{SO2}$ $\ce{SO3}$ $\ce{NO2}$ From the above we can conclude that $\ce{SiO2}$, $\ce{CO2}$ and ...
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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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31 views

Why does reduction always accompany oxidation and vice versa?

We've all learnt that the reduction always accompanies oxidation and vice versa Why is this so? Why is it not possible that a species releases an electron and the electron just "floats around"? Is ...
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Cathode gained mass in zinc electrolysis

I performed an electrolysis of zinc, using two zinc electrodes and a zinc nitrate solution. However, after leaving the electrolysis to run for 30 min, at about 0.4 A and 6 V, I discovered that the ...
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33 views

Reduction and oxidation in organic chemistry

What is the meaning of reduction and oxidation in organic chemistry? From what I learned in General chemistry - OIL RIG i.e oxidation is loss and reduction is gain (of electrons).But what do we say ...
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Is the following reaction redox? [closed]

Is the test of sulphur using sodium nitroprusside a redox reaction?
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What is formed when you leave iron (II) sulfate in plain air?

What is formed when you leave iron (II) sulfate in plain air? It was the question I found in textbook. Assuming that air is oxygen I solved it this way: $$\ce{FeSO4 + O2 -> Fe2O3 + SO2}$$ ...
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Dissolution of silver with dilute nitric acid

Which gaseous product forms when dilute nitric acid reacts with silver metal in the absence of air? A. $\ce{H2}$ B. $\ce{O2}$ C. $\ce{NH3}$ D. $\ce{NO}$ This question is from ...
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Purpose of ammine in Tollens' reagent

In this previous question the mechanism for the reaction of Tollens' reagent was outlined. As I understand it the oxidising agent in Tollens' is the diamminesilver(I) complex $\ce{[Ag(NH3)2]+}$ but ...
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70 views

Reaction of an organic compound with Reducing Agents

Suppose we have a chemical compound as : [Simplification of the structure : It is $\ce{-COOC_2H_5}$ bonded to a 5-carbon ring with one double bond and the ring is doubly bonded to $\ce{=O}$] ...
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Mercury into mercury oxide

How can I turn mercury metal into mercury oxide? I know that many metals will react with oxygen if enough heat is supplied in the presence of oxygen. If I heated up mercury enough and also supplied ...
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38 views

Single displacement reaction

Will sodium metal, if mixed well with iron oxide, displace the iron in a chemical reaction? I know thermite involves the mixture of aluminium powder and iron oxide, and the single displacement ...
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34 views

The hydrogen ion in acidified potassium manganate (VII)

Recently, I am playing with redox reaction and I come over a compound acidified potassium manganate (VII) ($\ce{KMnO4/H^+}$). I get confused that why they put $\ce{H^+}$ beside $\ce{KMnO4}$. Doesn't ...
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Why isn't dry CaCl₂ used to dry HCl gas instead of concentrated sulfuric acid?

In our chemistry books (like Concise Chemistry), it is given that concentrated sulphuric acid is used to dry $\ce{HCl}$ gas. But, concentrated sulphuric acid is a strong oxidising agent so, why isn't ...
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35 views

Stability constant for metal ion complex using reduction potential [closed]

Determine the stability constant of the zinc tetramine complex from the equations: \begin{align} \ce{[Zn(NH3)4]^2+ + 2e &-> Zn + 4NH3} & E(\text{red}) &= -1.04~\mathrm{V}\\ ...
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Plotting ΔG vs Temp for Electrochemical Reaction

I’m doing an electrochemistry lab that requires me to construct various galvanic cells in an attempt to solve for $\Delta H$, $\Delta G$, and $\Delta S$ values of an unknown. During one part of the ...
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79 views

How to determine the value for n in the Gibbs free energy and redox potential equation?

I am having a problem with this equation for redox potentials $$\Delta G=-nF\Delta E$$ In this equation I never am totally sure about what the value of $n$ should be, for example for the reaction ...
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31 views

Why does a reduced compound become a better electron donor?

When a compound gains an electron, why are they more likely to give them up (i.e. become stronger reducing agents)?
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Zinc in acidic permanganate solution?

How can this be described by redox equation? My attempt: Half reaction as follows: Then overall reaction:
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How can I balance the following equation atomically and electrically?

$$\ce{C2O4^2- + MnO2 -> Mn^2+ + CO2}$$ I think that the half reactions are $$\ce{C2O4^2- -> CO2}$$ $$\ce{MnO2 -> Mn^2+}$$ I am supposed to balance these by adding water, $\ce{H+}$ atoms ...
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586 views

If losing electrons means getting oxidized, then does it mean that ALL metals are reducing agents, since they themselves get oxidized?

I was just going through my last year's school textbooks and while I was reading this chapter on Redox, this above question crossed my mind. Shouldn't it be true that since ALL metals lose electrons ...
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37 views

Fluorination with xenon difluoride

Is this an error? Why is the nitro group reduced as the benzene ring is oxidized? I don't see any possible reducing agents here.. Also, what is the mechanism of aromatic fluorination by xenon ...
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22 views

What is the byproduct from hydrogenolysis of an acyl chloride?

What's the byproduct of this reaction? After all, it is a "lysis" reaction. So ... would HCl be a byproduct?
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57 views

Balancing Redox Equations - Half Reactions

How do I balance this using the half-reaction method: $$\ce{Zn(s) + HCl(aq) -> Zn^{2+} (aq) + H_2 (g)}$$ I would first split it up in its ionic components: $\ce{Zn(s) + H^+ + Cl^- -> Zn^{2+} ...
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How much ozone is produced by ionization of air and how turn ozone into oxygen

I want to make a plasma speaker. I'm worried about the amount of ozone being produced by the ionization of the air and it possibly not being a safe amount. Even if it doesn't produce a dangerous ...
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70 views

Corrosion of iron

First question regarding corrosion of iron: Why is anodic area always located at nicks and scratches, where energy state is high? (does"high [potential] energy" mean unstable structure?) ...
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Does hydrogen react with air at room temperature and pressure?

I have a container with 3% hydrogen and the rest is air. How fast the hydrogen will get oxidized by air? How much the reaction will speed up with increased temperature? Thanks so much.
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While electrolyzing concentrated aqueous sodium chloride, why is it that chlorine is discharged but not sodium?

Hydrogen and hydroxide both exceed sodium and chlorine in terms of reduction and oxidation potential respectively. While electrolyzing a concentrated solution of aqueous NaCl, it is known that ...
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Concentration cell lower half cell concentration from measured cell potential

I am trying to find the Ksp of silver thiocyanate: AgSCN(s) --> Ag+ (aq)SCN-(aq) but I need to first prove that the lower [Ag+] = 1.27-12 M, but don't know how to find it. The data I am given: ...
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67 views

Frost diagram and acidic/basic conditions.

The Frost diagram for sulfur shows the relative stability (in terms of cell potentials) of the possible aqueous oxidation states. What is the reason for the instability of higher oxidation states in ...
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79 views

Does this equation balance?

$$\ce{CaCO3 + 2H2O + Pb^{2+} -> Pb(CO3) + Ca(OH)2 + H2}$$ Does this equation balance? On the right you have lead with 2+ charge, whereas on the right its completely neutral. So my question is do ...
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96 views

Strongest oxidizing agents and reducing agent

I have to find out the strongest oxidizing agent and the strongest reducing agent in: $\ce{Cr(NO3)2(aq)}$ and $\ce{FeCl3(aq)}$. This is my current thinking: $\ce{Cr(NO3)2(aq)}$ Contains ...
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Why does the OAc group leave in the first step of Oxymercuration?

The above picture shows the first step of Oxymercuration. The electrons attack the Mercury atom but the OAc group leaves. Why is this? Hg is a transition metal with a number of available oxidation ...
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How do I go about balancing these equations?

I have to use oxidization number approach. $\ce{Co^2+ (aq) + H2SO3(aq) -> Co^3+(aq) + S2O3^2- (aq)}$ This is my approach so far: The change in Co is 1 electron, the change is S is 2 electrons, ...
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Ionize Hydrogen and Oxygen Gas in Electrolytic Cell?

As is well known, water can be electrolyzed into oxygen and hydrogen gasses. However, all redox reactions can be run in reverse. If I were to electrolyze water in 2 closed containers (in order to trap ...
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Is reduction potential equivalent to the ease of discharge?

Loosely speaking, is the reduction potential equivalent to the ease of discharge in the context of electrolysis? i.e. is it easier to discharge an ion with a higher reduction potential as opposed to ...
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CO detector reaction

I have recently bought a CO spot detector which is not working the way I intended for it. A CO spot detector is a analog carbon-monoxide detecting patch that changes color when it comes in contact ...
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Why do the pennies in the pre/post 1982 penny experiment sometimes dissolve completely?

USA pennies were nearly pure copper pre-1982. Post 1982 they are copper clad zinc. A common experiment in US high schools is to notch pennies with a file and add them to an HCl solution. The old ...
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Balancing a REDOX reaction using the oxidation number method, in acidic solution

I am trying to balance the REDOX equation shown below, but I got stuck after balancing the major atoms. Where can I go from here? I know I need to balance the H and O atoms, and make sure the charges ...
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Balancing REDOX reactions in a basic solution, when no H+ ions are present

I am trying to balance the following redox reaction, in basic solution. From what I have learned, to balance a redox reaction in basic solution you simply balance it as you normally would in acidic ...
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Oxidation and reduction [closed]

Separate this redox reaction into its component half-reactions. $$\ce{2K + Cl2 -> 2KCl }$$ Oxidation half-reaction: Reduction half-reaction. Use the e- for an electron
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Aluminum deoxidation gas

I am new to chemistry. I am looking for a gas that would de-oxidise aluminium. Which gases would work for that and at what temperature? Details: I need to sinter aluminium powder. But because the ...
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Reaction balance

I got this redox reaction on my exam that I didn't know how to balance. $$Sodium~iodate+sulphur~dioxide+water\ce{->}sodium~sulphate+sulphuric~acid+iodine$$, thus it would be: $$\ce{NaIO3 +SO2 ...
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424 views

Why does temperature affect cell potential?

The Nernst equation describes the relationship between cell potential and temperature. But why does temperature affect cell potential? My understanding is that the collision model of kinetics is not ...
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101 views

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 ...
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430 views

Ionic equation for reaction of iron (ii) chloride and zinc?

I know that the zinc half equation would be $\ce{Zn -> Zn^{2+} + 2e}$ However I am confused about the half equation for iron. I would think that since iron is completely displaced, it's oxidation ...
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317 views

Ionic equation for reaction of potassium permanganate with potassium iodide?

The half equation for the reduction of the permanganate would be $$\ce{5e- + 8H+ + MnO4- \rightarrow Mn^2+ + 4H2O}$$ But with regards to the iodide, I am very confused. I have seen some sources say ...
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518 views

Green Potassium Manganate and Sodium Hydroxide Equation

When a sample of green potassium manganate (VI), $\ce{K2MnO4}$, is added to aqueous sodium hydroxide, a brown black solid A and a purple solution of B are obtained. I know that the brown black solid ...
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How has Iodine gained electrons?

Two chromium atoms gain 3 electrons each. They go from 0 to 3+ Similarily, 6 iodine atoms go from -1 to 0, thus gaining one electron. However my textbook says that Iodine has lost electrons. How? ...