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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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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34 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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54 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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Electrolysis of water and production of O₂ gas [on hold]

Assuming that electrolysis is 100% efficient, 1 mole of gas=22.4dm^3 and 1 mole of e- = 100,000 C a. Write down the oxidation and reduction half-reactions of electrolysis of water b. Calculate the ...
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33 views

calculate original oxidation state of vanadium based on titration value [closed]

the oxidation number of vanadium in a complex ion was determined as follows. A 0.013 mol sample of the complex was dissolved in water and the solution was made up to the 100 cm3. A 10 cm3 portion of ...
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36 views

Redox reaction between tin(II) and permanganate in acidic solution [closed]

Consider the titration of a solution of $\ce{SnCl2}$ to $\ce{Sn(IV)}$ with an acidic solution of potassium permanganate, $\ce{KMnO4}$. Write down the balanced net ionic formula for the titration ...
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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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22 views

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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16 views

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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41 views

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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32 views

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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180 views

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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13 views

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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38 views

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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3answers
51 views

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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69 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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61 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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1answer
159 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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1answer
166 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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306 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? ...
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Reduction of amides

The reduction of an amide using LAH yields a primary amine . I looked up the mechanism over here. The mechanism suggests that the final main product (amine) is produced before giving the products a ...
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What property of zinc chromate makes it a good anticorrosion paint

What properties of zinc chromate make it a good anticorrosion paint? I know that stainless steel is protected by a layer of chromium oxide. Is it because the zinc chromate doesn't flake off the ...
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48 views

How does Zinc become oxidized when it's not in direct contact with Copper ions in a Galvanic cell?

Whenever Galvanic Cell is explained in textbooks/videos it usually starts by showing that if you put a piece of $\ce{Zn}$ in a $\ce{Cu^{2+}}$ ion solution the $\ce{Zn}$ will become oxidized and ...
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n-factor for ammonium nitrite?

The given reaction is $$\ce{NH4NO2 \rightarrow N2 + 2H2O}$$ The way I did it was $$\ce{NH4+ \rightarrow \frac{1}{2} N2 + 4H+ + 3e-}$$ and $$\ce{NO2- +3e- +4H+ \rightarrow \frac{1}{2} N2 + 2H2O}$$ ...
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56 views

Why is water considered ionic in fuel cells but otherwise covalent?

If water, $\ce{H2O}$ is a covalent compound formed by sharing of electrons, why is it said (in case of fuel cells) that formation of water from hydrogen and oxygen is a redox reaction (transfer of ...
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63 views

Redox reaction with tin and sulfuric acid solution

I need to write the redox reaction from tin and a sulfuric acid solution. Here is the solution: The first half-reaction: $\text{Sn}\rightarrow \text{Sn}^{2+}+2\text{ e}^-$ The second ...
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124 views

Does NaOH react with K to form NaOK or KOH?

I realized that the $\ce{-OH}$ group when it reacts with some metal like $\ce{Na}$ or $\ce{K}$ will replace the $\ce{H}$ element to form $\ce{-OK}$ or $\ce{-ONa}$: \begin{align} \ce{H2O + Na ...
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Why reduced atoms are more energetic?

For example, in glycolysis, $\ce{NAD+} $ is reduced to $\ce{NADH}$ and then it's more energetic. Why adding electrons to an atoms gives it more energy?
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The anode and cathode when corrosion happens

Let's say $\ce{Fe}$ reacts with $\ce{Cu^{2+}}$ ions. $\ce{Fe}$ would oxidize and therefore give electrons to $\ce{Cu^{2+}}$so that: $$\ce{Fe-> Fe^{2+} +2e-}$$ $$\ce{Cu^{2+} +2e^- ->Cu}$$ The ...
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Redox Half Reaction - Reduction

I can't seem to figure out this redox reaction. Is the charge on the Carbon in the $\ce{CO2}$ supposed to match the charge on the Carbon in the $\ce{CH3COO-}$? I am supposed to build a half ...
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Hydrazine as a reduction agent

When using hydrazine as a reduction agent to reduce graphene oxide, which is the product hydrazine oxidises to?
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220 views

Relationship between surface area of electrode and reaction rate of hydrogen in fuel cells

I am looking at the effects of increasing the surface area of which the flowing hydrogen fuel is in contact with the anode in a fuel cell. At the anode the hydrogen is catalytically split into ...
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What is actually a redox reaction?

I need to know what a redox reaction is. How could a redox reaction possibly be identified? Also, I have a confusion whether, $$\ce{H -> H+ + e-}$$ $$\ce{e- + Cl -> Cl-}$$ $$\ce{H + Cl -> ...
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210 views

Principle of potentiometric titration

In potentiometric titration between Ascorbic acid and Iodine when we plot the graph between EMF with volume of iodine consumed, we get a sudden decrease in emf at equivalance point,Why? It is also ...
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Sacrificial Anodes and Pit Corrosion

I have a slab of aluminum and one part of the slab will be exposed to a very corrosive environment. If I put a sacrificial anode elsewhere on the slab will the section that is exposed still be ...
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Why should the redox reaction happen between the copper ions and iron atoms?

I know that when $Cu$$^+$$^2$ ions react to $Fe$ atoms, it becomes $Cu$ + $Fe$$^+$$^2$. My question is, why? Copper atoms normally have 29 electrons. These means that in the K-shell there are 2 ...
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Reducing NOx with Ammonia. Practical in a gasifier?

Sorry if this is an outright stupid question. I am no chemist... For Nitric Oxide: $2{NH_{3}} + 2 NO => 2 {N_{2}} + {H_{2}} + 2{H_{2}O}$ For Nitrogen Dioxide: $2{NH_{3}} + 2{NO_{2}} => ...
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How to know if something will be a good oxidizing/ reducing agent? (Besides the activity of the metal)

One of first redox reaction I was taught in school, is probably single replacement. It is easy to predict cause all you need is a table of metal activity series. But then there are more complicated ...
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What reactions can take place for the reactants $\ce{Ag/Ca^2+}$ and $\ce{Mg/Cu^2+}$?

Explain the following experiments and their results. What is their chemical equations as well? When immersing a Magnesium (Mg) chunk inside aqueous solution of Copper ions (Cu(ii)), a red-brown ...
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1answer
34 views

Will happen or not?

I have a few questions, I'm really confused with my own answers so an explanations on why each of them can or cannot happen will be appreciated. A. Is $\ce{H+}$ capable of oxidizing $\ce{Cu_(s)}$? ...
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Oxidation of methane

In the reaction $\ce{CH_4 + 2O_2->CO_2 + 2H_2O}$ the $\ce{C}$ atom is oxidized. I can clearly see the addition of $\ce{O}$ atoms, however I don't see a change in Oxidation state. In the products, ...
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What can HI + red phosphorus reduce?

What can $\ce{HI}$ plus red phosphorus reduce? what happens if lactic acid is reduced by it? Does it reduce only the $\ce{OH}$ part, or does it reduce both the $\ce{CO2H}$ and the $\ce{OH}$ part?
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Clean silver with aluminum foil and *

I already have two questions touching on this subject and there is a third question as well. The thing is that all the other question talk about cleaning silver with aluminum foil and carbonated ...
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What is the chemistry behind cleaning silverware with aluminium foil

This question has a accepted answer on this site already: What happens during cleaning silverware? but the reason I ask the question again is because I found different "recipes" for the technique ...
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Clean tin with aluminium

I've been using aluminium foil and table salt to clean my silverware for a long time without actually concerning myself with the chemistry behind it. A couple of days ago i started digging into the ...
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139 views

How does the oxidation of NaI by sodium hypochlorite to give I+ work?

I'm in trouble with the oxidation of NaI by $\ce{NaClO}$, the reaction should give $\ce{I+}$ which then reacts by electrophilic substitution with an aromatic complex. As of now I've come to: $$\ce{ ...
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110 views

Does Iron (III) Sulfate react with copper?

As my understanding, there should be an oxidation-reduction reaction: $$ \ce{2Fe^{3+} + Cu \rightarrow 2Fe^{2+} + Cu^{2+}} $$ However, I always see the process using $\ce{FeCl_3}$ to etch ...