Reduction-oxidation reactions: all chemical reactions in which atoms have their oxidation state changed.

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Reaction mechanism of combustion of H2?

After a discussion about the usefulness of hydrogen fuel for cars with a friend of mine, I wondered what the reaction mechanism for combustion of $\ce{H}_2$ was. I only study (well almost) organic ...
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How to find out if ions are oxidised/ reduced based on half cell potentials

I have a hw question that I keep getting wrong and I need some help on? Assuming standard conditions, answer the following questions. (yes/no) Is $\ce{Fe^{2+}(aq)}$ capable of reducing ...
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can sodium persulfate etch or damage a titanium heater?

I use Sodium Persulfate to etch copper on a PCB process. I have been using glass heater on the etching tank but the glass is too fragile; it breaks too easily. I read that titanium heater is used ...
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40 views

On spontaneity of a redox reaction

Suppose we have a redox reaction and we want to see in what direction the reaction is spontaneous. We do this by comparing the standard reduction potentials of the sub-reactions available in the main ...
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49 views

What do the half-reactions need to be for balancing a redox reaction in an acidic medium?

Question: Balance the following reaction: $\ce{CuS + SO4^{2-} -> CuO + SO2}$ My Efforts: Number mentioned in the brackets oxidation number of S I have found out that the oxidation ...
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Why is coating with an oxide considered oxidation

I looked up the word oxidize and one of the definitions is to make it an oxide which is what happens when iron gets rusty(even though there is also iron hydroxide in rust). Another was to coat with ...
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Finding the Oxidation number

I have got the homework to balance the following redox reaction. $\ce{Cr(OH)3- + HO2- -> Cr2O7^{-2} + OH- }$(Basic medium) To balance this reaction first thing we need to do is to find the ...
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26 views

Is there a database which give reaction constant?

For instance, I have a chemical reaction like : $$\ce{Fe^{2+} + $0.5$O2 + H^{+} ->Fe^{3+} + $0.5$ H2O}$$ And I would like to use Action-Mass law, but I need to have equilibrium constant for this ...
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Any possible additives to a drain cleaner I use as a source of NaOH?

It is in pellets. And the box says main ingredient $\ce{NaOH}$ at least $30\%$ (I hope it's more). The box also says "aluminium catalyst". My goal was to take these pellets and dissolve them in water ...
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36 views

Reduction and Oxidation - Alternate definitions

Why is reduction defined as the gain of hydrogen? Is it because hydrogen has a very low electronegativity and easily donates its electrons to other elements? From what I understand reduction is ...
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21 views

Redox properties of methyl radical

The methyl radical, $\ce{.CH3}$, is a strong oxidant and a strong reductant according to Wikipedia. Why is this so? Any additional reasons to the ones below? I know that an oxidant itself is ...
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48 views

How does a simple alkaline battery work?

The basic + - electrolyte set up. Modern batteries and the like. How exactly do they work?
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Why do acids favor the oxidizer? And bases the reducer?

Simply put, why does adding acid to the cathode up the cell voltage? From what I understand, acids are proton donors. Do these positive protons attract electrons toward the cathode compartment of the ...
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Rust forming and being washed off by the same substance

I have noticed that when exposed to water for a few days the water turned the steel in my wagon into rust. After several more weeks the rust that formed is dissolved and once I pour the water out ...
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42 views

What are the oxidation states in Borohydride (BH4-)

The CRC Elecrochemical Series and the solution to our exercise suggest that the oxidation states of borohydride are -V for Boron and +I for Hydrogen. Since H (2.2) is more electronegativ than B ...
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58 views

On Spontaneity of the Redox Reactions

According to this Mc Graw-Hill link during a spontaneous redox reaction Gibbs Free Enthalpy must decrease and at the same time the change in the Gibbs Free Enthalpy is the maximum electric work that ...
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41 views

Kinetic validity; redox reactions

What's the kinetic validity of the following way of balancing the above redox reaction? I've done some searching of the literature; I've never come across oxide anions being mentioned in redox ...
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Why is the water reduction of oxygen favored in acidic conditions?

The standard reduction potential of diatomic oxygen in acidic conditions is +1.23 volts. However, the standard reduction potential of diatomic oxygen in basic conditions is only +0.40 volts. Why ...
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43 views

Can I perform electroplating with sodium carbonate and copper?

I want to avoid anything poisonous during electroplating. I can't avoid copper oxide though. I have dissolved $\ce{Na2CO3}$ in water and I'm trying to electroplate aluminium with copper: As you ...
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Can I use sodium hydroxide (NaOH) to remove oxides from metals?

Sodium hydroxide dissolved in water is a very strong base. I think this could mean it could de-oxidate the metal oxides during re-ox reaction. Basically, I ask whether the following happens: ...
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Rusting of an Iron nail at oil water boundary surface

Recently at school, I did some experiments on corrosion. Everything mostly went as expected, but the result in one of the test was quite baffling. This test had an iron nail in water with some of ...
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69 views

Can Lead (Pb) oxidize Tin (Sn)?

According to my textbook, element $\ce{X}$ can oxidize element $\ce{Y}$ if $\ce{X}$ was lower in the activity series. Lead is lower than Tin in the activity series table in the textbook, but the ...
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Which electrodes do not corrode at all?

I had used spare pieces of metal to perform electrolysis. They all had the disadvantage that they corrode when used as anode - and some of the oxides are toxic (copper, chromium). I've found that ...
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Can redox reactions involve only non metals?

When non metal react they form molecule, and whether the bond is polar or not, the elements in the molecular compound will not have charges what so ever, because they are not ionic. But can non metals ...
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Why is standard reduction potential an intensive property?

My book says that Since the number of electrons lost must equal the number gained, the half-reactions must be multiplied by integers as necessary to achieve the balanced equation. However, the ...
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Sulphur oxoacid forming

I got this reaction and I can't figure out the end products $$\ce{SO2 + S + CaO + Na2SO4 -> Na2S2O3 + ~?}$$ Guessing some calcium sulphur salt should form, but which one?
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Reduction of MnO₄⁻ to MnO₂ in alkaline solution

In acidic medium, $\ce{MnO4-}$ is reduced to $\ce{Mn^2+}$ ions while in alkaline medium, it is reduced to $\ce{MnO2}$. Why is it so?
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Balancing redox equation

So I had these two reactions that confused me .. I tried the standard way of balancing it (Putting oxygen number everywhere, +1,+2,-2 etc.) and then go on with it but it didn't work So anyways here ...
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In a redox reaction, why does more than one oxidation state of an element form?

Consider the reaction 100ml 10M $\ce{NaOH_{(aq)}} +$ 100ml 10M $\ce{NaHSO3_{(aq)} +}$ 100mL 0.01M $\ce{KMnO4_{(aq)}}$ In the picture posted here, the left columns give information on the Molarity of ...
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33 views

Calculating Redox Potential; Coupled Reactions

For the reaction of silver and hydrochloric acid to form silver chloride: would the following be the correct way to couple the below two half reactions? $\ce{2Ag(s) + 2Cl^- ->2AgCl(s) + 2e^-} ...
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131 views

Why is it that neither silver nor copper react with a strong acid?

$\ce{Fe}$, $\ce{Mg}$, $\ce{Ni}$, $\ce{Pb}$, $\ce{Sn}$, and $\ce{Zn}$ all react when they (in solid form) are submerged in an acid solution with the presence of a strong acid like $\ce{HCl}$, but ...
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What exactly is the “oxygen reduction reaction”?

Is it $\ce{O2(g) + 4H^+(aq) + 4e^- \rightarrow 2H_2O(l)}$ and are there multiple types of ORR? See here for context: http://www.nature.com/srep/2014/140122/srep03821/full/srep03821.html
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Moles of Reduction Product

Regarding the above question, how would one solve it? Would it be valid to simply say that I know that 6 electrons are being transferred because we have this skeleton equation (balanced for ...
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Electrolysis of Strongly Basic Water

What happens when strongly basic water is electrolyzed? I know that the electrolysis of water in strongly acidic solution involves hydrogen protons; will these protons still be involved in strongly ...
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Explanation for the reactions in a saltwater battery with zinc and copper electrodes

I am a physicist, not a chemist. I'm trying to get a basic understanding of the reactions taking place in a battery using a saltwater electrolyte with copper and zinc terminals. I'm writing a general ...
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63 views

How does oxygen fight odors? (Deodorant ad)

I saw an ad on tv last night for Mitchum deodorant that showed big text on the screen that said "OXYGEN eliminates all odors!" or something similar. Their website indeed claims "Our exclusive formula ...
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51 views

Why does 2-methyl-2-propanol need heat (for oxidation)?

In Chemistry class, we had to combine dissolved $\ce{K2Cr2O7}$ with 2-methyl-2-propanol and heat it for the oxidation to occur. But why does it need heat, while dissolved $\ce{K2Cr2O7}$ with for ...
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Electrolysis of Water

What is the mechanism for the electrolysis of water? I understand that hydrogen and oxygen gas are made, but how exactly does this happen when electrons are passed through water? A diagram would be ...
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Conjugate Theory and Redox

I'm trying to apply conjugate theory, which I can apply very well to acids/bases, to redox. Can you verify my logic, which I have broken down below? 1) I know that solid sodium is a strong reducer. ...
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Corrosion of CuSO4 with AgNO3

I have $\ce{AgNO3}$ (aqueous) reacting with $\ce{CuSO4}$. I'd like to know how the Reduction-oxidation reaction works in this case.
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Which ion of iron is produced in a reaction between iron and copper(II) sulfate?

Using these equations: \begin{aligned} \text{(Fe2):}&&\ce{ Fe + CuSO4 &-> FeSO4 + Cu}\\ \text{(Fe3):}&&\ce{ 2Fe + 3CuSO4 &-> Fe2(SO4)3 + 3Cu} \end{aligned} Beginning ...
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What is difference between aluminium mercury alloy and gallium aluminium alloy?

Aluminum mercury alloy is used as a chemical reagent to reduce compounds, such as the reduction of imines to amines,in this case mercury destroy aluminium oxide layer which protect aluminium to react ...
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$\ce{O^{2-}}$ Anion in Redox - Origin?

How come the oxygens transferred in redox reactions are always the $\ce{O^{2-}}$anion? For example, I have this set of rules, and the rules are implicitly referring to the $\ce{O^{2-}}$ anion, a ...
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Balancing Redox Equations with $\ce{H^+}$ or $\ce{H_3^+O}$

Is it preferable to balance redox equations with $\ce{H^+}$ or $\ce{H_3^+O}$? I think the latter, because first, the bare hydrogen proton doesn't exist in water solution. So why write down something ...
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Balancing Redox Equations

I was taught to balance redox equations with acid/base considerations. Instead of arbitrarily adding $\ce{H^+}$ and $\ce{HO^-}$ ions and memorizing separate rules for acidic and basic solutions, I was ...
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53 views

How to prove that reaction is possible

I have been given task to write possible reaction equations, determine oxidizer, reducer, write corresponding electron-equations and calculate electromotive force (I do not know if that is what you ...
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Does a patina on a knife prevent rust?

Before I begin, I think it's worth mentioning that I know little about chemistry and even less about knives. My question is this, having seen many people talk about how patinas work and the best ...
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How to calculate the equivalent weight or N-Factor of compound(acid, salt, base or etc) using electrolysis concept

Our sir, told us about the concept of equivalent weight using electrolysis and Faraday's Law of electrolysis. We got to know ...
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Oxidiation Number for Anaerobic Respiration

What is the Oxidiation Number for the anaerobic respiration of yeast: $C_6H_{12}O_6 \longrightarrow C_2H_5OH + CO_2 + ATP$
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Reduction of Iron (III) to elemental Iron - How do I calculate the mass of carbon needed?

The equation for reducing iron (iii) oxide with heated carbon is: $\ce{Fe2O3 (s) + 3C (s) + 3CO (g)}$ The mass of carbon needed to produce $100~\mathrm{g}$ iron is? I honestly do not understand how ...