What is Oxidation: Definition and 208 Discussions

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.

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  1. Tam Le

    Why Does Copper Not React with Lead Nitrate?

    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...
  2. N

    Oxidation of sulfide to sulfate

    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...
  3. N

    How do I calculate the cell potential?

    < 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...
  4. caters

    Why is my stainless steel spoon oxidizing?

    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?
  5. T

    What is the Oxidation Number of Pb in Pb(O)2?

    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...
  6. S

    Trigger for a Zn oxidation reaction in a battery Reference

    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...
  7. S

    Trigger for a Zn oxidation reaction in a battery

    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...
  8. Elvis 123456789

    Is 3FeCl2 to 2FeCl3 and Fe(s) a Disproportionation Redox Reaction?

    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...
  9. D

    The Smell of Garlic and Enzymatic Oxidation

    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...
  10. R

    Why do lanthanides have +3 oxidation state(most stable).

    Lanthanides can exhibit 2,4 states also but why 3 is most stable one?
  11. gracy

    Oxidation Reaction: SO2 to H2SO4?

    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.
  12. D

    Calculating Oxidation State of Nitrogen in 2NO + O2 -> 2NO2

    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? ...
  13. C

    Validity of the Pauling Scale of Electronegativity?

    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...
  14. S

    Oxidation of cyclohexanol to hexane-1,6 dioic acid?

    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...
  15. S

    XPS for different oxidation states

    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...
  16. caters

    How is coating with an oxide 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 an oxide. Now how is coating with an oxide oxidation? Does it catalyze the oxidation by...
  17. Conservation

    Oxidation of Metal Using a Generator

    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...
  18. T

    How does partial pressure of O2 affect thermal oxidation time for Si?

    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...
  19. Q

    Oxidation reactants and products

    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...
  20. M

    Mass balance on oxidation of ammonia for production of nitric acid

    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...
  21. B

    Oxidation number in acidic medium

    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?
  22. I

    Copper - oxidation and reduction

    Why the electrical purification of copper involves both an oxidation and a reduction process.
  23. C

    Redox reactions oxidation number method

    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...
  24. K

    Corrosion Vs Oxidation: Differences?

    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.
  25. B

    Oxidation State & Shapes of Ni(CO)4

    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...
  26. R

    Exploring Oxidation and Reduction in d4 Transition Metals

    Why is Cr2+ reducing while Mn3+ oxidizing when they both have d4 configuration?
  27. C

    Oxidation (Charge) State and Screening

    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?
  28. P

    Examine Factors Affecting Pyrite Oxidation in Acid Sulphate Soils

    Hello I really need help how to examine factors what affect the oxidation of pyrite in acid sulphate soils and how to measure it
  29. C

    Will the formation of a dative bond change the oxidation number?

    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?
  30. K

    Oxidation Reduction (redox) Balancing

    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...
  31. A

    Why does oxygen in bleach react with other substances?

    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...
  32. A

    What is meant by oxidation and reduction?

    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?
  33. S

    Help in The Oxidation Number Method ?

    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...
  34. B

    Iodide Oxidation by Hydrogen Peroxide

    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...
  35. M

    Determination of oxidation numbers in caffeine

    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...
  36. H

    Covalency and Oxidation Number in Covalent Compounds

    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...
  37. S

    Oxidation and reduction problems

    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...
  38. C

    Confused about oxidation number

    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 :)
  39. T

    What's Going On When Iron Electrodes Are Electrolyzed in Sodium Hydroxide?

    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...
  40. R

    Balancing Redox Equations Using Oxidation Numbers

    Question Balance the following redox using oxidation number. Please show all steps. NaIO3 + NaI + HCl -> NaCl + I2 + H2O Attempted Solution So first I assigned oxidation number: NaIO3 + NaI + HCl -> NaCl + I2 + H2O 1+ 5+ 2- | 1+ 1- | 1+ 1- | 1+ 1- | 0 | 1+ 2-...
  41. P

    Oxidation state and chiral configurations

    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...
  42. P

    What is the oxidation mechanism of KMnO4 on alkanes?

    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...
  43. M

    Find Oxidation State of S in S2O32- Reducing Cl2

    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...
  44. D

    Find oxidation number of platinum

    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...
  45. S

    Electrolysis and electroplating electrolytes and oxidation states

    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...
  46. agnibho

    Oxidation Number to balance a redox reaction

    Homework Statement Balance Cl2+NaOH -> NaCl + NaClO3 + H2O
  47. J

    Why Does KMnO4 Oxidise I- to I2 in Acidic Medium but to IO3- in Alkaline Medium?

    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?
  48. nukeman

    Quick question about Aluminium ? How to find its oxidation state ?

    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...
  49. S

    Oxidation states of transition metals when reactions occur

    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...
  50. J

    PARTIAL oxidation of methane as energy source

    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...
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