Read about redox | 22 Discussions | Page 1

  1. P

    Chemistry Solving for electron activity given pH and ratio of redox elements

    I've written out the half reaction 8e- + 9H+ + SO42- = HS- + 4H2O and I know the logK = 4.25 (that's the constant mentioned in the prompt) I've written out the equilibrium statement of 10^4.25 = ([x^1/8]*[H2O^1/2])/([10x^1/8]*[e-]*[(10^-8.2)^9/8] However, from there, it seems like I have two...
  2. K

    Redox titration

    Cl2(g) + 2I–(aq) -->I2(aq) + 2Cl–(aq) (reaction 1) [2S2O3^(2-)(aq) + I2(aq) --> S4O6(2-)(aq) + 2I–(aq) (reaction 2) Why isn't n(I2)(reaction 2)=2n(S2O3^(2-))(reaction 2). I don't see why this is wrong. <edit: remove size and italics>
  3. J

    Copper (II) salts and SO2: a question

    The reaction below moves left to right (I expect it has an equilibrium somewhere): SO2(g) + 2 CuCl2(aq) + 2 H2O → H2SO4(l) + 2 HCl(l) + 2 CuCl(aq) I'm wondering if copper (II) acetate will work in place of copper (II) chloride: producing acetic and sulfuric acids instead of hydrochloric and...
  4. C

    Why is activity of solvated components equal to 1?

    Homework Statement Consider the following reaction $$\mathrm{Ni^{2+}_{(aq)} + H_2S_{(g)} \to Ni_{(s)} + S_{(s)} + 2H^{+}_{(aq)}}$$ What are the activities of the terms in the reaction? Homework Equations The activity is defined as ##a = c/c^\circ## in ##\mathrm{ mol \, dm^3}## 3. The...
  5. alphaj

    Is this a redox reaction?

    Quick note: Sorry for dominating the homework help board, guys! But, I wanted to say thank you to everyone who replies to my excessive questions. This forum's input has become integral to me as I am in a position now where I can't go to my teacher for help because of the logistics of commuting...
  6. Wrichik Basu

    A problem in Redox Titrations (Kjeldhal's Method)

    Homework Statement :[/B] 1.08g of ##NH_4 Cl## is boiled with 62ml ##\frac {N}{2}## ##NaOH## to expel ##NH_3## completely. 44ml of ##\frac {N}{4}## ##HCl## is required to neutralise the excess alkali. Calculate the percentage of ##NH_3 ## in ##NH_4 Cl##. Answer given: 31.5% Homework Equations...
  7. T

    Electron transfer and oxidation state

    When beryllium donates a pair of electrons to oxygen, that's oxidation, and the metal is Be(II). When carbon and oxygen share 6 electrons, 2 from carbon and 4 from oxygen, this is also oxidation. Of carbon. Even though it got more electrons, and even, I heard, has a negative charge. When...
  8. B

    Why there are infinite ways to balance this Redox equation?

    Homework Statement Balance :- $${Cl_2O_7} + {H_2O_2} {\longrightarrow} {ClO_2^-} +{O_2} + {H^+}$$ Medium :- basic Homework Equations The Attempt at a Solution $${\stackrel{+7}{Cl_2}\stackrel{-2}{O_7}} + {\stackrel{-1}{H_2}\stackrel{-1}{O_2}} {\longrightarrow}...
  9. ashsully

    Application of REDOX

    Homework Statement Hi all, I'm fairly new to physics forums so cut me some slack for being a noob. I've just noticed that my brand new snowboard's edge has rusted (oxidised). I live in Australia and it's been stored in my room receiving sunlight everyday. I'm guessing this probably caused the...
  10. D

    Balancing a redox reaction

    Hi there: I'm trying to balance a reaction in which methane is oxidized by citric acid in solution. Both methane and citric acid will be transformed into carbon dioxide. To begin, I checked that the reaction is indeed a redox reaction. C6H8O7→CO2 So, I calculated the oxidation number for...
  11. Stephanus

    Antioxidant, reducing agents

    Dear PF Forum, Lately, I'm trying to understand the benefits of antioxidant. What is the difference between antioxidant and reducing agents? 1. Reducing agent react with (reduce) oxidizing agent to CREATE NEW molecule(s)? 2. Antioxidant reduces the oxidizing agent so it has an additional(s)...
  12. P

    Explain why Zn is released and write the general equation.

    Homework Statement We throw clean Zn in a HCl solution and see that nothing happens. We add 2-3 drops CuSO4 and some kind of gas starts to release. Why dos this happen? Write the equation Homework Equations Zn+HCl->ZnCl2+H2 The Attempt at a Solution I know that equation and also...
  13. P

    Could you help me with this electrolysis equation?

    Homework Statement Write the water electrolise of NaOH. Homework Equations NaOH+H2O->H2+O2+NaOH The Attempt at a Solution 2NaOH+2H2o->2H2+O2+2NaOH I thought to write 2H2O->2H2+O2 If I am given the mass of NaOH (which in one problem I am), then how am I supposed to find the mas of H2O for...
  14. P

    Find the mass of Ag around the Nickel pole

    Homework Statement A nickel pole is put in an AgNO3 solution with volume 50ml and concentration 0.1 mol/litre until the concrentration is 0.02 mole/litre. Find the mass of Ag that is put around the Nickel pole. Homework Equations 2AgNo3+Ni->Ni(NO3)2+2Ag number of moles= concrentration*volume...
  15. P

    Find in which case the Zn pole mass is greater

    Homework Statement A pole of Zn is put in a FeCl2 solution and in a HgCl2 solution. FInd in which case the mass of the pole of zinc has become grater and when less Homework Equations Zn+FeCl2->ZnCl2+Fe Zn+HgCl2->ZnCl2Hg The Attempt at a Solution As Zn is much active than Hg than it goes in...
  16. Dong Aleta

    [Compound + Compound = Compound] Reactions: A question

    Hi! I noticed that almost all of the [Compound + Compound = Compound] reactions that I have encountered do not involve any transfer of electrons, or are not oxidation-reduction (redox) reactions. Can it be generalized that all [Compound + Compound = Compound] reactions are not redox reactions...
  17. T

    Basic concept doubts in redox reactions

    Homework Statement [C2O4]-2 ------> CO2 Find if the reaction is oxidation or reduction and determine the no. of electrons lost or gained by carbon. Homework Equations The Attempt at a Solution I started with finding the oxidation states of both elements. It's 3+ and 2- for carbon...
  18. Elvis 123456789

    Is this a 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 Equations The Attempt at a Solution...
  19. G

    Why reduced atoms are more energetic?

    For example, in glycolysis, NAD+ is reduced to NADH and then it's more energetic. Why adding electrons to an atom gives it more energy?
  20. C

    Surface area contact with catalyst effect on hydrogen redox

    I have also posted this question here: Relationship between surface area of electrode and reaction rate of hydrogen in fuel cells, but I really need an answer before tomorrow morning so I hope you don't mind me posting it here as well! I am looking at the effects of increasing the surface area...
  21. D

    Oxidation - gain of oxygen?

    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? ...
  22. S

    What is the importance of the solution in an electrochemical cell?

    I'm wondering about the importance of the electrolytic solution in an electrochemical cell. For example, we have Zn/ZnSO4 and Cu/CuSO4. According to the electrochemical series, Zn will reduce Cu, and we will have a reaction. Zn(s) -> Zn2+(aq), Cu2+(aq) -> Cu(s). So there MUST be Cu2+ in the...