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.

learn more… | top users | synonyms

1
vote
1answer
27 views

Reaction of chlorine with hot/cold solution of hydroxide

When chlorine reacts with cold solution of say potasium hydroxide, the disproportionation goes to lower oxidation states: $\ce{Cl2 + 2 KOH -> KCl + KClO + H2O} $ Whilst with hot solution the ...
0
votes
0answers
21 views

Balance Redox Reactions [on hold]

I have to balance the following redox reaction: $$\ce{ Zn + NaNO3 + NaOH -> Na2ZnO2 + NH3 + H2O}$$ I tried to balance it using the acidic method and got: $$\ce{10H2O + 8Zn + 2NaNO3 -> 8NaZnO2 ...
0
votes
0answers
16 views

Confusion regarding coexistence of chemical compounds [on hold]

The pair of compounds that can exist together is: (1) FeCl3, SnCl2 (2) HgCl2, SnCl2 (3) FeCl2, SnCl2 (4) FeCl3, KI I didn't know how to decide this!
3
votes
1answer
32 views

Which species gives electron in the following reaction?

In a given reaction like this: $$\ce{FeO4^2- + 3e^- + 8H+ <=> Fe^3+ + 4H2O}$$ From where does the electron come in the acidic medium, as there is no other species to get oxidised in the ...
-1
votes
1answer
15 views

Balancing redox reactions [closed]

I was given two ions and were asked to construct a balanced redox equation. How am I supposed to know whether is it acidic (adding H+ to balance) or alkali (OH- to balance) condition. Correct me if ...
0
votes
0answers
8 views

Galvanic cell.(the ZnSO4 container to be a zinc made container) [closed]

[1]: http://i.stack.imgur.com/jHWyv.jpg IF the A jar is made of Zn. I meant the container of ZnSO4 to be a Zn made container . THEN would the reaction occure?
-4
votes
0answers
19 views

Balance Redox Equation in Acid Solution [closed]

Balance the following redox equation in acidic solution using the method of half-reactions: $C_2H_5OH _{(aq)}$+ $I_3^{-}$$_{(aq)}$ $->$ $CO_{2}$ $_{(g)}$+ $CHI_3$ $_{(aq)}$ +$ I^{-}$ $_{(aq)}$ + ...
0
votes
0answers
17 views

How to calculate n factor for salts in this reaction?

My source says : For salts which react such that no atom undergoes change in oxidation state , n-factor for such salt is the total moles of cationic /anionic species replaced in 1 mole of the salt . ...
-1
votes
0answers
19 views

Can someone explain this reaction of an imine involving a carbonyl shift? [closed]

This looks to me to be a reduction but when I try to work it out mechanistically I get an alcohol with an amine group and I can't see how to convert from there to the product. Thanks!
-3
votes
0answers
68 views

Determination of mass of iron and insoluble filler [closed]

A bottle contained 100 tablets. Most of each tablet was an iron(II) salt. The remainder of the tablet was a filler of calcium sulfate with small amounts of other substances. All the tablets were ...
0
votes
0answers
36 views

Can I convert elemental nitrogen to nitrous oxide?

Can I convert nitrogen to $\ce{N2O}$, to conduct barking dog reaction, where it's needed as oxidizer?
0
votes
0answers
24 views

Cell Potential Problem with Unusual Electrode

The problem reads: Calculate the cell potential, $E$, for a silver-silver chloride electrode immersed in $0.800~\mathrm{M}$ $\ce{KCl}$ at $298~\mathrm{K}$. Given: $$\begin{align} ...
0
votes
0answers
15 views

Chemistry Redox Reactions

$$\ce{SO4^2- + H2O2 + 2H+ -> SO2 + O2 + 2H2O}$$ In the above chemical reaction,I am having trouble in identifying the oxidized a reduced species. My guess is: sulfur has reduced but I can't work ...
3
votes
1answer
33 views

How to balance a redox equation in molecular form?

I've spent a while trying to balance this equation in molecular form with no success. $$\ce{Cu + HNO3 -> Cu(NO3)2 + 2NO + H2O}$$ I need to find the coefficient of HNO3, which is 8. However, this ...
3
votes
1answer
198 views

How to identify a redox reaction?

I don't understand how to identify a redox reaction. The answer key shows the correct answer as D, but I'm confused as to why. Which balanced equation represents a redox reaction? $$A. ...
6
votes
1answer
49 views

Stereoselectivity differences in Lindlar's catalyst and Na/NH3?

Why does using the Lindlar's catalyst form cis-alkenes whereas $\ce{Na/NH3}$ forms trans-alkenes?
1
vote
1answer
25 views

Which procedure(s) will allow a student to differentiate between solid sodium sulfate and solid sodium sulfite?

I. Make solutions of each and look for a precipitate when added to 0.10 M Ba(NO3)2. II. Add crystals of each to 0.10 M HCl and watch for bubbles. III. Make solutions of each and test with a pH ...
0
votes
3answers
40 views

How can Chlorine has an oxidation number of -3 in (CLO2)^-1

First of all I am new here and I don't think this site has an INTRODUCE ME subboard nevertheless I am just preparing(self studying) for my GCSE. Coming back to the point, I am studying Redox reactions ...
4
votes
1answer
56 views

Mechanism of the oxidation of alcohols with KMnO4

Many oxidising agents, like chromate, dichromate, iodine in $\ce{NaOH}$ etc. seem to work via ester formation and elimination. For example, chromic acid will react with the $\ce{-OH}$ of alcohol to ...
-1
votes
0answers
27 views

Are gold ions the most powerful pure element agent for dissolving metals in water?

You can use hydrogen ions (basically acids) to dissolve metals in water with redox reactions. $$ \begin{array}{c c c c} & E_{\ce{2H^+ + 2e^- -> H2}} & = & 0{V} \\ + ...
3
votes
1answer
29 views

Why is sulfuric acid used in the Jones oxidation of alcohols?

When oxidising primary alcohols, $\ce{K2Cr2O7}$ is used because it's a useful & readily available oxidising agent. Why does the sulfuric acid need to be added? Does it have to do with the ...
1
vote
2answers
32 views

Is it possible to write a redox reaction with two oxidations and one reduction together?

Let's take the Redox reaction between ${MnO_4}^-, {C_2O_4}^{2-}$ and ${SO_3}^{2-} $ Is it possible to write the complete reaction as below or do I need to consider the two reactions separately? ...
0
votes
0answers
21 views

Electrode Potentials, Redox Reactions

Construct a balanced equation for the reaction between $\ce{Cr^2+}$ ions and $\ce{Cr2O7^{2-}}$ ions in acid solution and calculate the standard potential. In my answer I wrote this equation : ...
0
votes
1answer
50 views

How to balance the reaction equation of potassium permanganate, calcium oxalate, and sulfuric acid step by step?

I have been desperately trying to balance the following equation, and finally (ultima ratio) used an online program to get it done (posted the same question there as well). $$\ce{KMnO4 + CaC2O4 + ...
3
votes
1answer
68 views

What is the pH of the solution (redox question)?

For the following reaction: $$\ce{NiO2(s) + 4 H+(aq) + 2 Ag(s) -> Ni^2+(aq) + 2H2O(l) + 2Ag+(aq)}$$ $$ E^\circ = 2.48\ \mathrm V$$ Calculate the $\mathrm{pH}$ of the solution if $E = ...
0
votes
0answers
49 views

The reaction between nitric acid and iron II sulfide

...yields NO2, H2O, Fe3+, and S. I can spot the half reactions reducing the nitric acid to NO2 and H2O and oxidizing the Fe2+ to Fe3+, but how does S2- get oxidized to S? I am not familiar with this.
1
vote
1answer
39 views

Experimentally finding order of a reaction

For the reaction of bromocresol green and bleach, I was supposed to conduct an experiment to find the order of the reaction with respect to bleach. To do this, I used a fixed amount of bromocresol ...
0
votes
0answers
22 views

Which substance participates readily in both acid-base and oxidation-reduction reactions?

Which substance participates readily in both acid-base and oxidation-reduction reactions? $\ce{Na2CO3}$ $\ce{KOH}$ $\ce{KMnO4}$ $\ce{H2C2O4}$ And why? I know $\ce{KOH}$ ...
0
votes
0answers
37 views

Adding reduction potentials?

Will it be wrong to add reduction potentials of two intermediate reactions to get reduction potential of net reaction(just like as we do in adding enthalpies and applying Hess's law)? What is the ...
1
vote
0answers
26 views

Will bases typically precipitate silver atoms from silver ions?

In class I learnt that one can dissolve many substances using acid and that this can be predicted using standard electrode potentials. For example, $$\begin{align} \ce{Zn &-> Zn^{2+} + 2e^-} ...
1
vote
1answer
159 views

Fe 2+ and MnO4- titration?

As a lab experiment, I am preparing a mixture of iron tablets dissolved in sulfuric acid so they can be titrated against $\ce{MnO4-}$. The tablet contain insoluble filler material. Why is it ...
0
votes
1answer
31 views

Quick question about the reduction of iron oxide using carbon

When reducing iron oxide with carbon, must the substances be set alight or do they only need to be heated. Also, when the iron is formed will it immediately oxidise in the air?
1
vote
1answer
112 views

Why does bromine react with iron(II) but not iodine?

My question comes from the answer (C) to this question: Firstly, (correct me if I'm wrong please) I thought that the answer could either be C or D since the other answers are negative ions which ...
2
votes
1answer
49 views

Trying to displace iron from ferrous sulphate heptahydrate using aluminium foil but nothing has happened

I started by dissolving the sulphate into water and filtering it as I noticed there was a dirty residue lying at the bottom. (I am using ferrous sulphate that is commonly used in gardening.) I then ...
0
votes
0answers
31 views

Redox balancing

How do we balance redox reactions like this: $$\ce{H2O2 + I2 -> HIO3 + H2O}$$ I tried to split $\ce{H2O2}$ as well as $\ce{HIO3}$ into 2 each and then carry out the 3 changes in ON and then add ...
14
votes
1answer
1k views

Counterintuitive Reaction of Aluminium On Steel Balls

There is a certain video which I just watched about 2 large cast iron balls. If the balls are struck together, no reaction happens, but if one is covered in aluminium foil and then struck, a large ...
0
votes
0answers
21 views

Cleaning Copper

When you have oxidized copper coins and you pour lemon juice over it and add sodium chloride, a reaction takes place and the copper becomes shiny again and tiny bubbles appear. What is happening ...
7
votes
1answer
116 views

Single step transformation of a carboxylic acid into an aldehyde

What are the different ways of transforming a carboxylic acid into an aldehyde in a single step ? (as opposed as for instance first transforming it to an ester then to an aldehyde) The bottom of this ...
1
vote
1answer
55 views

Conversion of carboxylic acid to alcohol

Is it feasible to convert carboxylic acids to alcohols? I know the reverse is done during the oxidation of alcohols (e.g. in the production of vinegar), but is it possible to do it the other way ...
-2
votes
0answers
42 views

how does a daniell cell work

I am highly confused as to why many chemistry textbooks when discussing a Daniell cell put that a zinc sulfate solution will convert to Zn$^+$ ions. When Zinc sulfate reacts with water, it should form ...
7
votes
1answer
77 views

Why do steel and iron not passivate the way aluminum does?

When aluminum is exposed to oxygen a micro layer or film of oxide appears on the surface and oxygen cannot penetrate any further. With iron or steel, however, oxygen continues to reach into the ...
5
votes
1answer
59 views

Current in a galvanic cell

I was looking through chemistry textbooks to find out how to determine how much current a galvanic cell should generate and what affects that current value. However, I did not find anything: textbooks ...
0
votes
0answers
25 views

Galvanic Cell and Standard emf series signs for the voltages

In my lecture slides on Galvanic cells and Nernst Equation, there is an example for a $\ce{Zn}$ and $\ce{Ni}$ reaction, with $\ce{Zn}$ being the Anode (oxidation reaction: $\ce{Zn -> Zn^2+ + 2e-}$. ...
2
votes
1answer
34 views

How to calculate the electrochemical potential of Iron(II/III) and saturated calomel electrode?

Set up an electrochemical cell where the cathode is the system in question B, $\ce{Fe^2+ -> Fe^3+}\ E = 0.68~\textrm{V}$, whereas the anode is a saturated calomel electrode ($0.244~\mathrm{V}$ ...
0
votes
1answer
27 views

Reduction of chlorate with phosphorus

Given $$\ce{10KClO3 + 3P4 -> + 3P4O10 + 10KCl}$$ If 52.9 grams of $\ce{10KClO3}$ reacts with excess $\ce{P4}$, what mass of $\ce{3P4O10}$ could be produced? How many moles of $\ce{KCl}$ could be ...
1
vote
0answers
37 views

Redox reactions for chemistry test

What is the redox reaction between $\ce{H2SO4 + Zn}$? My effort: I know the half reaction for $\ce{Zn}$ is $$\ce{Zn -> Zn^2+ + 2e-}$$ and it is being oxidised. $\ce{H2SO4}$ doesn't form ...
0
votes
1answer
41 views

What are the oxidizing and reducing agents in the reaction?

Here's the reaction. $Pb(s) + PbO_2(s) + 2H^+ + 2HSO_4^- \rightarrow 2PbSO_4(s) + 2H_2O(l)$ I thought that, since the solid lead is going from 0 to 2+ it is being oxidized, and in the half reaction ...
0
votes
1answer
52 views

how to identify reaction medium by looking at the equation ( for h2o2)?

$\ce{Ag2O + H2O2 -> 2Ag + H2O + O2}$ My book says the medium is alkaline as $\ce{H2O2}$ gives $\ce{O2}$ on reduction only in alkaline medium only but $\ce{O2}$ is produced in acidic medium too. Is ...
0
votes
0answers
32 views

Output of the Sugar & Sulfuric Acid Reaction?

When a reaction of sugar and sulfuric acid occurs, some form of carbon is produced. Is this carbon bonded as graphite? If not, than what is it bonded as? Edit 0: I had the wrong reaction originally. ...
1
vote
1answer
27 views

Prevention of rusting

I'm currently learning about corrosion prevention, and have a question regarding galvanising. Say that you have an iron nail. You galvanise it (coat it in zinc), so that is doesn't rust by preventing ...