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.

-1
votes
0answers
15 views

Chemical equation for oxidation of primary alcohol with acidified potassium permanganate

I have seen many sources describing the oxidation of alcohols with dichromate in great details; however, none or few gives a satisfactory description and explanation of the oxidation with acidified ...
-1
votes
2answers
45 views

Reduction of ester in presence of ketone group

As there is no ring expansion I'm assuming that a carbocation should not form at ester carbon as it leads to ring expansion. But is there any an exception to it? Also the hint provided along with this ...
0
votes
1answer
52 views

How to oxidize tantalum? [on hold]

I am interested in learning how to oxidize tantalum. I have seen some tantalum rings that the sellers say is a permanent smokey blackish color. But I've spoken to some people that say tantalum cannot ...
0
votes
1answer
28 views

Fuel cell potential for the electrolysis of ammonia

I am trying to calculate the fuel cell potential for the electrolysis of ammonia with the following equation: ...
1
vote
2answers
55 views

Can antimony pentafluoride be made by adding hydrogen fluoride to antimony trifluoride?

I was looking at how the strongest acid was made and I found something I did not understand. On the Wikipedia page for antimony trifluoride it shows the production of $\ce{SbF3}$ using $\ce{HF}$: $$\...
-1
votes
0answers
20 views

electric potential of a redox reaction

I'm wanting to know how to figure out the electric potential of a redox reaction with the following half reactions: $$\ce{S (-II) - 8e- -> S (VI)}$$ $$\ce{4O(o) + 8e- -> 4O(-II)}$$ I can't find ...
-3
votes
1answer
76 views

Burning magnesium ribbon [closed]

I know that this might sound wrong but, in the reaction $$\ce{2 Mg(s) + O2(g) → 2 MgO(s) + energy}$$ isn't oxygen supposed to be oxidised as it has excess electrons $(\ce{O^2-})$ and can donate a ...
0
votes
0answers
28 views

Reaction between copper and silver(I) nitrate in aqueous medium

What is the reaction between $\ce{Cu}$ and $\ce{AgNO3}$ taking place in aqueous medium? The answer given was: "Only" oxidation of $\ce{Cu}.$ My concern is: how is only oxidation of $\ce{Cu}$ ...
-1
votes
2answers
45 views

Is this balanced redox equation correct? [closed]

I'm trying to balance an equation using oxidation numbers $\ce{MnO4^- + H+ + Cl- -> Mn^2+ + Cl2 + H2O}$ my suggestion: $\ce{MnO4- + 8H+ + 5Cl- → Mn^2+ + 2.5Cl2 + 4H2O}$ the 2.5 $\ce{Cl2}$ is ...
5
votes
2answers
104 views

How do metals split the oxygen double bond during corrosion?

For a metal like $\ce{Mg}$ to corrode into $\ce{MgO}$, the double bond in $\ce{O2}$ must break. Since the dissociation energy of $\ce{O2}$ is 500 kJ/mol, using estimates from the Boltzmann ...
0
votes
1answer
45 views

Why does hydrogen burn spontaneously in fuel cell at room temperature?

It's well known that if you mix $\ce{H2}$ and $\ce{O2}$ in ambient conditions, the $\ce{H2}$ will be stable indefinitely, and will only react with $\ce{O2}$ to form water when ignited by a flame. The ...
1
vote
1answer
35 views

Redox titration or iron(II)

The concentration of $\ce{Fe^2+(aq)}$ can be determined by a redox titration using A. $\ce{KBr}$ B. $\ce{SnCl2}$ C. $\ce{KMnO4}$ (basic) D. $\ce{KBrO3}$ (acidic) Can anyone please ...
1
vote
1answer
86 views

Reaction of potassium with water

In general, when we put potassium into water, it will produce potassium hydroxide and hydrogen: $\ce{2K + 2H2O ⟶2KOH + H2}$ However isn't the following reaction also possible? $\ce{2K + H2O ⟶K2O + ...
0
votes
3answers
44 views

Can Iron(III) oxide oxidize elemental iron in a nitrogen environment under room temperature without any catalysis? [closed]

Will there be electron transfer to allow this process to happen: $\ce{2 Fe(III) + Fe(0) -> 3 Fe(II)}$
-1
votes
0answers
31 views

Products of Redox Equations [duplicate]

I was just wondering how would you know the products of a redox equation, or if that could even be derived from just knowing the reactants. For example when Potassium permanganate reacts with a ...
-1
votes
0answers
29 views

Sulphuric acid in as oxidant [duplicate]

I find difficult to understand how do I get to the products of the following reaction: $$\ce{2NaBr(s) + 2H2SO4(aq) -> Br2(l) + SO2(g) + Na2SO4(aq) + 2H2O(l)}$$ after checking the oxidation ...
0
votes
0answers
43 views

Reaction of DIBALH with alkyl cyanides

I was recently studying reactions involving DIBALH (diisobutyl aluminium hydride) and saw that it's reaction with alkyl cyanide yielded R-CH2NHOH according to Jerry March whereas in Solomons the ...
1
vote
1answer
50 views

What are the half reactions for the redox reaction between SO2 and iodine?

What are the half reactions for the redox reaction between $\ce{SO2}$ and iodine? The relevant chemical equation: $$\ce{ SO2 + H2O + I2 -> H2SO4 + 2HI}$$ This is what I think it is, not sure if ...
4
votes
1answer
168 views

Reaction between copper(II) iodate and iodide

I was attempting the following question from IChO 1989, which involved balancing of redox equations. One may just expect this to be a typical iodate-iodide redox reaction, usually employed in ...
0
votes
0answers
24 views

Electric potential of a redox reaction (without solids)

I need someone to help me with a problem: We have a solution which is $\pu{0.1 M}$ of $\ce{KMnO4}$ and $\pu{0.1 M}$ $\ce{Fe^2+}$ and has $\mathrm{pH}=0$. Given the electrical reduction potential of ...
2
votes
2answers
240 views

Leaching of copper using zinc

Why can we not use zinc for extracting copper from a solution containing $\ce{Cu^2+}$ ions even though it is a better reducing agent than $\ce{Fe}$? I am studying metallurgy and I cannot understand ...
0
votes
0answers
39 views

Can a cation form a bond with only the oxygen in hydroxide ion?

$$\ce{Al2O3 + 2 NaOH → 2 NaAlO2 + H2O}$$ In this reaction between an amphoteric oxide and a base, I do not understand how $\ce{Al}$ makes a bond with oxygen atoms since the water is found in the ...
0
votes
0answers
35 views

Why does the following “Battery” experiment work?

I did the following experiment: Experimental setup: Two electrodes (one made out of Iron,the other made out of Copper) are put into a (bluish) Copper(ii) sulfate lotion. Then, one connect a ...
2
votes
1answer
67 views

Why do Cu⁺ ions spontaneously form copper metal and Cu²⁺ ions in solution?

The standard electrode potentials for three reactions involving copper and copper ions are: $$ \begin{align} \ce{Cu^2+(aq) + e- &-> Cu+(aq)} &\quad E &= \pu{+0.15 V} \\ \ce{Cu^2+(...
0
votes
0answers
13 views

Nitrate reaction with iron minerals

I am trying to find literature or an answer to what happens to nitrate as it comes in contact with iron oxides. Does the nitrate get reduced to ammonium in all cases of iron(II/III) oxides? What is ...
0
votes
1answer
42 views

Disproportionation of 2 KO₂ + 2 H₂O → 2 KOH + H₂O₂ + O₂

How is the following reaction a disproportionation reaction? $$\ce{2 K\overset{-1/2}{O}_2 + 2 H2\overset{-2}{O} ->2 KOH + H2\overset{-1}{O}_2 + \overset{0}{O}_2}$$ In this, the OS are $-1/2$, $-2$...
1
vote
0answers
35 views

Can carbon dioxide be used as oxidant for iron?

Determine whether it is possible for $\ce{CO2}$ to be an oxidant for $\ce{Fe}$. Justify your choice by comparing the corresponding half reactions. I found the following half-reactions, both on ...
0
votes
1answer
34 views

How can I find the emf of a cell given the individual reduction and oxidation reactions and their respective potentials? [duplicate]

If I am given the individual oxidation and reduction half-equations, how can I find the emf of the combination? For example: $$ \begin{align} E^\circ(\ce{Fe^3+}/\ce{Fe^2+}) &= \pu{0.77 V}\\ E^\...
-2
votes
2answers
77 views

Two cells are connected in series. If x g of silver are deposited in cell 1, what volume of oxygen is given off in cell 2? [closed]

I got the answer correct but I'm pretty sure my methodology was wrong. How would you solve such a question?
0
votes
1answer
40 views

In a galvanic cell, why do electrons move through the wire from zinc to copper?

I understand that there is aqueous $\ce{Cu^2+}$ in this scenario which pulls on the electrons from the zinc causing the electrons to move through the wire, but how does the electronegativity of $\ce{...
1
vote
1answer
42 views

Reverse Cannizzaro reaction to make aldehydes?

Is it possible (and practicable) to reverse Cannizzaro reaction (disproportionation of aldehydes to carboxylic acids and alcohols) to produce aldehydes from carboxylic acid and alcohol without need to ...
6
votes
1answer
419 views

Will heating of KClO3 be considered disproportionation?

In all examples of disproportionation I have seen, there is one particular atom whose oxidation state is both increasing and decreasing to give rise to different products For example, on heating ...
2
votes
1answer
32 views

Corrosion of iron: no electron pushing mechanism?

Why does the oxidation-reduction reaction between iron, water, and $\ce{O2}$ gas to form rusts lack an electron pushing mechanism and a specific sequence of steps? $$\ce{4Fe^0(s) + 3 O2(g) + 2n H2O(l)...
0
votes
0answers
23 views

Negative Voltage for Full Redox Reaction?

I have a question about voltages including redox reactions. I know that half equations may have negative voltages when choosing what is undergoing reduction, and what is undergoing oxidation in a ...
1
vote
1answer
44 views

What is the balanced chemical equation for a redox reaction between a lithium-cobalt battery and a graphite electrode?

I'm doing a project for my last year of secondary school on lithium cobalt batteries and got confused about the equation. This is the only equation I can find (source: www.science.org.au): \begin{...
2
votes
1answer
54 views

Oxidation of Sodium Hydroxide in Ethanol?

So I read recently that: Alcoholic solutions of sodium hydroxide will oxidize in air, turning brown. First is this true? And if so what is oxidizing? I can't think of what sodium hydroxide ...
0
votes
0answers
18 views

What type of acid (and how much) needed to generate Chlorine Dioxide gas when added to Sodium Chlorite (for odor removal)?

I have several lbs of Sodium Chlorite (flakes), which I would like to use to generate Chlorine Dioxide gas in order to remove odors from rooms, autos, boats, etc. There are commercial products sold ...
0
votes
2answers
234 views

The equivalent weight of HNO3 in the following reaction [closed]

The equivalent weight of HNO3 in the following reaction is ‘x’, then the value of x/21 is 3Cu+8HNO3⟶3Cu(NO3)2+2NO+4H2O in this I atempted by using redox formulas but my answer is comming 1 but ...
0
votes
1answer
90 views

Does reduction/ oxidation take place separately at a half cell electrode?

In the redox reaction chapter, we learn that oxidation and reduction go hand in hand. The oxidising agent oxidises by accepting the electron released by the reducing agent and gets reduced in the ...
4
votes
1answer
196 views

Electrolysis of water: Which equations to use? (IB Chem)

There is a list of standard electrode potentials at 298 K from the p. 23 of IB Data Booklet 2016. Which of the following equations (forward/backward reactions), from the two possible ones involving ...
3
votes
3answers
96 views

What defines a discharged battery?

In the case of an AA Alkaline battery, what actually happens inside the battery once it is fully discharged? What components of the battery change as we use it?
4
votes
1answer
114 views

Redox Combustion Reactions

Consider a combustion reaction like the complete combustion of ethane. Here is what I have for the complete combustion as well as the oxidation and reduction: $$\ce{\overset{-3}{C}_2\overset{+1}{H}_6 ...
1
vote
1answer
57 views

Equation for reaction between chlorine fluoride and potassium bromide

The equation given in the answer key was $$\ce{ClF + 2KBr → KCl + KF + Br2}$$ However won't the $\ce{KCl}$ also react with $\ce{ClF}$ to form $\ce{KF}$ and $\ce{Cl2}$, resulting in the net reaction ...
1
vote
3answers
107 views

What is the flow of electrons, cations, and anions in a voltaic cell (please see image attached)?

This is an IB question. The mark scheme says that the correct answer is A and only A. But I believe B is also correct. The following is my thought process. Since A is more reactive, it undergoes ...
-1
votes
1answer
44 views

What do electrons usually do when lead acid battery is idle?

Lead acid batteries operation are governed by Redox reactions for charging and discharging. But, what do electrons usually do when lead acid battery is idle? And why? Assumptions: Say more ...
-2
votes
4answers
103 views

Reduction Potentials [closed]

Standard electrode potential values can be used to judge the reducing ability of a metal. When I was introduced to this topic a simple picture was painted: you put a metal into a solution of its ions. ...
0
votes
3answers
77 views

Confusion on electrode potentials

Standard electrode potential values can be used to judge the reducing ability of a metal. When I was introduced to this topic a simple picture was painted: you put a metal into a solution of its ions. ...
2
votes
1answer
48 views

Determining the half-reaction equations for extraordinary redox reaction? [closed]

I have the following question stated in the science teacher exam: Write the half-reaction equations for the following reaction by using oxidation numbers: $$\ce{Na2SO3 + Na2CrO4 -> ...
0
votes
1answer
103 views

The role of temperature in Nernst equation

When measuring a non-standard voltaic cell’s electrode potential, regardless the standard conditions, as long as the concentration of product and reactant the same, a non-standard cell’s potential ...
0
votes
1answer
50 views

Understanding the setup of a chemistry lab about redox

In chemistry lab we were looking at oxidation and reduction reactions. To determine the relative activity of several metals we observed reactions between the metals and aqueous solutions of dissolved ...