Redox (reduction–oxidation, pronunciation: RED-oks or REE-doks) is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the actual or formal transfer of electrons between chemical species, most often with one species (the reducing agent) undergoing oxidation (losing electrons) while another species (the oxidizing agent) undergoes reduction (gains electrons). The chemical species from which the electron is removed is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced. In other words:
Oxidation is the loss of electrons or an increase in the oxidation state of an atom, an ion, or of certain atoms in a molecule.
Reduction is the gain of electrons or a decrease in the oxidation state of an atom, an ion, or of certain atoms in a molecule (a reduction in oxidation state).Many reactions in organic chemistry are redox reactions due to changes in oxidation states but without distinct electron transfer. For example, during the combustion of wood with molecular oxygen, the oxidation state of carbon atoms in the wood increases and that of oxygen atoms decreases as carbon dioxide and water are formed. The oxygen atoms undergo reduction, formally gaining electrons, while the carbon atoms undergo oxidation, losing electrons. Thus oxygen is the oxidizing agent and carbon is the reducing agent in this reaction.Although oxidation reactions are commonly associated with the formation of oxides from oxygen molecules, oxygen is not necessarily included in such reactions, as other chemical species can serve the same function.Redox reactions can occur relatively slowly, as in the formation of rust, or much more rapidly, as in the case of burning fuel. There are simple redox processes, such as the oxidation of carbon to yield carbon dioxide (CO2) or the reduction of carbon by hydrogen to yield methane (CH4), and more complex processes such as the oxidation of glucose (C6H12O6) in the human body. Analysis of bond energies and ionization energies in water allow calculation of the redox potentials.
According to my chemistry textbook, Cu will not be oxidized by Pb(NO3)2, for Cu is lower on the activity series relative to Pb; Cu will not react with Pb(NO3)2.
Why is that? Copper should still be able to oxidize regardless of its position on the activity series. So, why does its position on...
Hello, I would need with this task:
Write a balanced equation for the oxidation of dissolved H2S to sulfate by dissolved oxygen. Indicate the oxidation states of the redox-sensitive elements involved.
- For each redox couple, write the oxidized and reduced species in an equation and balance...
< Mentor Note -- thread moved to HH from the technical chemistryforum, so no HH Template is shown >
I was given this problem:
A voltaic sell uses the reaction 4Fe3+ + H2 --> 2Fe2+ +2H+.
Find the cell potential when [Fe3+]=1.50 M, PH2=.50 atm, and [Fe2+]=.00100 M and the pH of both anode and...
I noticed on 1 of my stainless steel spoons that a film of Iron(II) oxide(which is a black rust) formed. I have been taught that stainless steel will not rust. So why would a stainless steel spoon be oxidizing?
Homework Statement
The problem is:
Find the oxidation number of each element in the compound: Pb(O)2
I said oxidation number of Pb = x, O = -1 since this is a peroxide, therefore oxidation number of Pb is plus 2. However, the solution manual says O is -2 and thus Pb is 2.
But elsewhere, for...
Who is the trigger of the oxidation reaction. Copper which attracts electrons from the Zinc or solution which makes Zinc losing electrons and become positively charged. I am struggling to understand what actually makes Zinc to enter the solution and leave 2 electrons behind. If there is no wire...
Who is the trigger of the oxidation reaction. Copper which attracts electrons from the Zinc or solution which makes Zinc losing electrons and become positively charged. I am struggling to understand what actually makes Zinc to enter the solution and leave 2 electrons behind.
If there is no wire...
Homework Statement
Determine the oxidizing agent, reducing agent, element oxidized, element reduced, # of electrons lost per atom, and # of electrons gained per atom. State if the reaction is not redox.
3FeCl2(aq) ------> 2FeCl3(aq) + Fe(s)
Homework EquationsThe Attempt at a Solution...
Hello,
We are working on project at school about garlic breath.Here is the article I have read in Popular Science magazine which gave me and idea.The article was about how to cure garlic breath and it gave some solutions about it.And I find these two(I copied them below from the original...
Is it right to say sulfur dioxide is oxidized to sulfuric acid? SO2 is converted into H2SO4, hydrogen is added so it should be reduction rather than oxidation.
2NO + O2 -> 2NO2
"Oxidation of NO"
So a reactant - 2NO doesn't seem to lose an electron, it only gains an additional oxygen atom. So, I guess, oxidation is also gain of an oxygen? ...
I propose the Pauling Scale is not valid in all circumstances, and other scales of electronegativity would do better to predict the behavior of electron density in molecules:
Electronegativity seems to be poorly defined for such a widely used chemical property: a 'tendency' of an atom or...
Homework Statement
is it possible to use conc HNO3 instead of H2SO4 to allow the reaction of oxidation of cyclohexanol to haxane-1.6 dioic acid to occur?
how can the reaction occur? cyclohexanol is seconary alcohol , it should be oxidised to ketone am i right? but it's oxidised to carboxylic...
Dear All,
for different oxidation states of the same element in X-ray photoelectron spectroscopy measurements, should the full width half maximum (FWHM) value be the same for all? Is this a parameter to fix in this case for the fitting?
I am studying an amorphous transition metal oxide thin...
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 an oxide. Now how is coating with an oxide oxidation?
Does it catalyze the oxidation by...
Hi all, this question may sound incredibly obvious to a degree of trolling, but I was having difficulty finding an online source that dealt with this subject.
When one connects a metallic plate to, say, a positive end of a voltage source, is the metal actually oxidizing and changing to +1...
Hi guys,
I'm trying to use thermal oxidation with Si wafers in order to get SiO2 to use for electric components. I've been trying to find out how the partial pressure of the gases used (O2 in this case, it's a dry oxidation) affect the oxidation time, but I haven't been able to find an...
1) Question:
Consider the oxidation of OCS in strongly basic solution by bromine. The products are carbonate ion and sulfate ion. What is the ratio of reactant hydroxide ion to product bromide ion?
2) Considerations and processes (outlined in attached picture of work but I'll rewrite...
Homework Statement
The following chemical reaction takes place inside a reactor where 80% conversion is obtained with an equimolar mixture of NH3 and O2 fed at the flow rate of 100 mol/h.
4NH3 + 5O2 ⇔ 4NO + 6H2O
What are the output rates of all species?
There's a diagram shown where...
Hi everyone,
In my school I was given a problem. It's that Cr2O7-2 + H2S in a acidic medium. And my teacher told that Chromium becomes Cr+3 .
I want to know is there such a way to calculate the oxidation number in acidic medium. Or is it required the experience?
1) Problem Statement
2) Relevant Equations3) Attempt at Solution
For question d, I realize in this case that the substance that is oxidized and reduced is the same molecule : iodine.
How do I proceed then as the next step would ask for you to find the change in oxidation numbers and multiplying...
Hi guys,
Until now I thought that oxidation and corrosion are the same. But I am not sure. Are they one and the same?
Why oxidation at high temperatures is important? How does that reduce part life?
Thanks.
Homework Statement
In Ni(CO)4 each carbon monoxide acts as a ligand coordinating to nickel. Suggest two possible shapes for Ni(CO)4; what is the oxidation state of Ni?
The Attempt at a Solution
The oxidation state of Ni seems to be likely to be 0, because carbon monoxide itself is...
Why exactly does an increase in the oxidation state of an element (i.e., higher positive states) reduce the screening of core electrons? For example, why would fewer electrons in a d state alter (increase) the effective charge experienced by a p state?
Consider NH3, if it forms a dative bond with an H+ to form an ammonium ion, will the oxidation number of N change from +3 to +5? My reasoning is that it uses 5 electrons in bonding.
Is that correct?
When balancing oxidation reduction reactions involving acids or bases, what (in the case of acids) allows you to add H+ ions to one side of the reaction and H2O to the other, or in the case of bases, OH- and H2O to balance out hydrogen/oxgen? Normally you are not allowed to just add random...
In the case of bleach (NaClO), why does the oxygen leave this molecule to react with other things? I understand that bleach leaves a NaCl residue and that the oxygen portion of bleach is responsible for its ability to kill bacteria and oxidize various other chemicals. I only ask this due to...
what is meant by oxidation and reduction and what are the differences between them?Though there is oxidation number why there is no number to represent reduction?
Help in "The Oxidation Number Method"?
Homework Statement
I just learned how to balance the redox reactions with this method, but there is something I don't understand ...
Look at this example :
Cu+HNO3 = Cu(NO3)2+NO2+H2O
after making the number of electrons gained and lost equal we get...
In my chemistry lab we prepared the following solutions:
Buffered Iodide Solution
25 mL acetic acid/sodium acetate buffer
6mL of 0.5 % starch solution
6 mL of 1.0M KI
fill to the 250 mL mark with distilled water
0.025M Thiosulfate Solution
5 ml of 1 M Na2S2O3
fill to the 200 ml mark...
Hi,
The formula of caffeine is C8H10N4O2. The oxidation numbers of O & H are -2 & +1 according to the book. How do I determine the oxidation numbers of C or N.
Note: The substance is a molecular substance so we cannot apply the following rule: "the oxidation number of an atom in a monatomic...
Homework Statement
NCl_{3}
What is the Co-valency / Oxidation number of Nitrogen in this Covalent compound ?
Homework Equations
I think the table of electronegativity might be useful
The Attempt at a Solution
Nitrogen must be "-3" since it is more electronegative than Chlorine.
The...
When something is oxidized, it gains oxygen, loses hydrogen or loses electron. However, if the substance gains something else other than oxygen then it won't be considered oxidation anymore? For instance H+ +OH- -->H2O so in this case it seems that the H+ gained oxygen from OH- but actually the...
guys anyone can help me ?
im bit confused when talkin about oxidation number in alkyl group
like
R-NO2
or
R-CN
when this compound react with reducing agent like H2
can somebody explain me? most example in book or internet doesn't use hydrocarbon reaction
thank you :)
I've got a question that is bugging me
If I have a concentrated sodium hydroxide solution and electrolyze it with iron electrodes, some of the possible reactions at the positive electrode are
2H2O -> O2 + 4H++4e-. Eo = -1.23 V
4OH- -> O2 + 2H2O + 4e-. Eo = -0.40 V
Fe -> Fe2+ + 2e-. Eo = 0.44...
I'm doing this same problem found on the following link for a biochemistry homework.
http://www.chegg.com/homework-help/questions-and-answers/nucleoside-phosphorothioates-synthetic-nucleotide-analogs-used-enzymology-molecular-biolog-q1481931
My question is regarding both finding the...
Hi,
I've been searching for the oxidation mechanism of KMnO4 on alkanes (aryl derivatives like toluene). All I found was some web sites telling me the overall reaction and that the mechanism is either unimportant or too complicated for their purposes. I found some little notes that it has a...
Homework Statement
One mole of aqueous S2O32- ions reduces four moles of Cl2 molecules. What is the oxidation state of the sulphur containing product of this reaction?
Homework Equations
The Attempt at a Solution
oxidation state in S2O32- = +2
since 4moles of Cl2 are reduced...
Homework Statement
Hello...
Seems like an easy question, but I'm notquite sure though.
Find the oxidation number of platinum in the following compound:
Pt(NH3)2Cl(NO2)Homework Equations
The Attempt at a Solution
If I just put Pt = x, and I know that (NH3) is neutral = 0, and Cl = -1, the...
When electrplating copper with a dilute NaCl aqueous solution and the anode is iron while cathode is platinum what will the results be? Will copper form cations or will the OH- be oxidised? Also, if we use concentrated NaCl will there be any difference? I'm thinking that the copper shouldn't be...
Why in acidic medium KMnO4 oxidises KI ( I-) to I2 but in alkaline medium to IO3 -
KMnO4 is a stronger oxidising agent in acidic medium right then why doesn't it oxidise I- to IO3- in acidic medium too?
Homework Statement
I am struggling a bit with naming compounds.
Al2(Cr2O7)3
Now, I know its aluminum dichromate, and the way to find this was KNOWING the oxidation state of Al being +3 - How am I suppose to know that? How do you find that out when all you have is a basic periodic...
When metals such as sodium react with an acid, a salt and hydrogen gas is produced. and we know for sure the oxidation state of sodium in the compound will be +1. But for other metals such as iron, when they rest with acids which oxidation state do I use? I'm unsure if I'm supposed to use the...
Methane from natural gas could be a great source of energy (eg. in thermoelectric plants), but the need to curb CO2 emissions stands in the way.
I wonder whether one could get useful energy from some partial combustion reaction of CH4, that yields H2O plus some carbon-containing solid that...