Reaction Definition and 1000 Threads

  1. N

    What is the Wittig reaction mechanism?

    Can anyone please walk me through the mechanism as this question does not make sense to me. I do have some understanding of the general mechanism. The answer is B) but I don't understand how to get there. The confusing aspect to me, is the structure of the ylide.
  2. Q

    Solving Reaction Mechanisms: A "For Dummies" Explanation

    Homework Statement Reaction: 2A --> C Step 1: A <-> M (fast) Step 2: M + A -> C (slow) What is the observed rate law? Homework Equations Rate = k[A][B][...] The Attempt at a Solution The observed rate law seems to be k[A]^2. However, why is it so? Why does the rate...
  3. Q

    Is Sodium Metal the Reducing Agent in Its Reaction with Water?

    Homework Statement When sodium is dropped into water, aqueous sodium hydroxide and hydrogen gas are produced. Which of the following are correct regarding this reaction? 1) Sodium metal is the reducing agent. 2) There are no spectator ions. 3) In the balanced net ionic equation, all...
  4. Manish7

    Why Doesn't Tetanus Infection Cause an Inflammatory Reaction?

    As i was passing reading tetanus and its causating bacterium ,pathogenesis, ,clinical manisfestations, i found that it is present as spores in soil and gains entry in body through wounds (except in neonatal tetanus ), germinates and then starts secreting toxin tetanospasmin leading to...
  5. A

    Can the Mass of Oxygen in a Compound be Determined from Combustion Products?

    Hello everyone! I have a question: Let's say we have a 6g sample of a compound that has C, H and O. This sample is burned with excess oxygen. I want to know if it is possible to recover the mass of O in the original compound from the mass of H2O and CO2 that will be produced (from...
  6. F

    Rate of Reaction: Calculating with Hydrogen Peroxide & Catalase

    Homework Statement Hello all, I'm currently in high school and I'm doing a biology experiment with catalase reacting with hydrogen peroxide. I have measured the total amount of gas produced in terms of mL during the reaction which took place over 30 seconds. Throughout the experiment I'm...
  7. gauss44

    Can a reaction be exothermic due to increased kinetic energy?

    Homework Statement Examkrackers Lecture question - MCAT Prep book 116. A student holds a beaker of pure liquid A in one hand and pure liquid B in the other. Liquid A has a higher boiling point than liquid B. When the student pours a small amount of liquid B into liquid A, the temperature of...
  8. F

    Interpretation of Cross Section of p,n reaction mb or mb/MeV

    Dear Forum : I'm reading a cross section data of 20MeV proton + 16O reaction from ICRU 63. ( as attachment and link http://ppt.cc/qf-9 ) The total cross setion of (p,n) reaction is 4.372mb However, the cross section of emitting neutron of energy between 0 to 1.5MeV is 0.91 mb / MeV. The...
  9. K

    Reaction Force of Rod at 90 and 180 Degrees

    Homework Statement a uniform rod of mass m and length L is free to rotate in the vertical plane about a horizontal axis passing through its end. the rod is released from rest in the position shown by slightly displacing it clockwise. Find the hinge reaction at the axis of rotation at the...
  10. S

    Strontium carbonate Acetic acid reaction

    I wanted to make strontium acetate but it didn't get hot (like when I mix calcium hydroxide with acetic acid). Does that mean it didn't work?
  11. B

    What is the energy released from a complete fission of 1kg of 235U (in joules)?

    The binding energy (BE) per nucleon for 235U is 7.6 Mev. The 235U undergoes a nuclear fission to produce two fragments both having a BE of 8.5Mev. What is the energy released from a complete fission of 1kg of 235U (joules)? Here I assumed that it breaks into two 118X element. Therefore...
  12. Hyo X

    Doubling reaction recipe while maintaining concentration

    Say we are running a chemical reaction of some kind, in liquid, in a round bottom flask. We have a solvent, two reactants, a product, and the reaction is under stirring, reflux (volume maintained) and constant temperature. In my mind, if we simply double the volume of all the reactants...
  13. F

    Action-reaction pairs, concerning gravitational force &normal reaction

    I would like to know how it is possible that I can be at rest on the surface of the Earth (relative the the Earth of course). My main cause for confusion is the action reaction pair that occurs when I stand on the surface of any solid material. The normal reaction nornal reaction a-r pair...
  14. N

    Why does a higher activation energy usually mean a slower reaction?

    Why does a higher activation energy usually mean a slower reaction? Doesn't activation energy just tell us whether or not a reaction will take place or not based on if the particles have enough energy to meet the activation barrier? How is it related to the rate of the reaction?
  15. anubodh

    Finding Reaction with High Density, Reversible Process

    Sir, i desperately want to know a reaction in which the resulting product has more density than the reactants and which can be reversed easily (prectically) with minimal or no loss of energy.Please reply.Thanks..
  16. N

    Determine the enthelpy of formation to find the enthelpy of reaction

    Homework Statement NH3 + O2 --> NO + H2O Enthalpies of formation NO: 91.3 kJ H2O: -241.8 kJ NH3: -45.9 kJ Homework Equations delta h = sum*moles enthalpy of formation of products - sum*moles enthalpy of formation of reactants The Attempt at a Solution = [(1)(91.3) +...
  17. P

    Knowing that a reaction has multiple steps?

    Hello, is there a way to eliminate the possibility of a reaction having one single step? For example, the reaction NO_2(g) + CO(g) \to NO(g) + CO_2 (g) appears to me to be single stepped, but my textbook gives the reaction in multiple steps and does not elaborate on how the individual steps...
  18. Q

    Armature Reaction & Brush Shifting

    Referring to a DC generator: one way to counter armature reaction is to shift the brushes. But I don't get how it works. The direction of armature flux also changes when the brushes are shifted, so why does the MNA (magnetic neutral axis) not also rotate further.. If it does rotate further...
  19. N

    Reaction - glycerolem + potassium permanganate

    Hello, I have a question: Why potassium permanganate reacts with grycerolem as it reacts? Spontaneous combustion, the violet flame ... I found only a complicated explanation. Please, can you explain it to me simply? Thank you!
  20. M

    Tension in cable and reaction force

    Homework Statement Homework Equations The Attempt at a Solution For this problem, what I am confused about is the fact that the Z direction parts of the tension will tend to rotate in a direction different from the Y components of the tension and the 850 lb vertical force. I am not sure how to...
  21. M

    How Do You Calculate Recycle Stream Values in Chemical Reaction Processes?

    Homework Statement Problem 12.20 Homework Equations The Attempt at a Solution For this problem, I am having a hard time getting any values for the streams, so I am stuck at stream G and K and can't figure out how much is going into G since I don't know the liquid recycle stream. I...
  22. I

    Action Reaction on a discus thrower.

    Hi there, I am trying to understand the physics acting on a discus thrower, namely at their feet when they throw a discuss. first the player spins to pick up momentum for the discus, he or she does this by pushing on the ground but when the actual discus leaves the hand, is there an action...
  23. WaterMelllon3

    Redox reaction formulas or corrosion formulas?

    I was just wondering if anyone has some redox reaction formulas or corrosion formulas? Cheers Darryl
  24. R

    Action reaction pair of magnetic force

    I am not able to understand reaction of magnetic force and how it is equal to qvb ?
  25. J

    Estimate the standard reaction Gibbs energy of the following reaction:

    Homework Statement "Estimate the standard reaction Gibbs energy of the following reaction: N2 + 3 H2 ‒‒> 2 NH3 at 100K and at 1000K." Homework Equations ΔS(T2) = S°(T1) + ∫ n Cp dT/T ΔG = ΔH ‒ TΔS Given data: http://imgur.com/MBakUEB (may need to right-click and select...
  26. D

    Alkali metal oxide reaction with water.

    I am confused as to why the following happens: K_2O + H_2O\rightarrow 2KOH^- Does the potassium hydroxide no longer react with the water? Why exactly is this a base? How does the potassium end up bonding with hydroxide?
  27. Saitama

    EMF of a disproportionation reaction

    Homework Statement Consider the following sequence of reactions occurring in the acid medium. All emf (standard) are measured at ##25^{\circ} C## and expressed in volt unit: $$MnO_4^-\stackrel{0.564}{\rightarrow}MnO_4^{2-}\stackrel{2.26}{\rightarrow}MnO_2\stackrel{0.95}{\rightarrow}Mn^{3+}...
  28. P

    What are the Corresponding Reaction Forces in a Suspended Bowling Ball System?

    Homework Statement A bowling ball is suspended from a ceiling hook using a thin piece of rope. If the rope is exerting a 65 N force upward on the ball, describe the corresponding reaction force in terms of: (a) its magnitude (b) its direction (c) on what object it is exerted (d)...
  29. G

    What happens to atoms that havent reacted in a chemical reaction?

    So let`s say that we have a chemical reaction with liquid oxygen and liquid hydrogen, but we`ve got very little hydrogen, and very much oxygen. As we pour these two liquids together they react with on another and create water. However since there was a very much bigger amount of oxygen than...
  30. Z

    What color will the final product of the copper nitrate reaction be?

    Cu(NO3)2(aq) + 2 NaOH(aq) → Cu(OH)2(s) + 2 NaNO3(aq) This is a chemical reaction I'll be doing soon for my chemistry lab. And I was wondering, since the product is blue, and as is the reactant, how can I tell I've used up all the cupric nitrate and it has all reacted? Note: and the NaNO3...
  31. M

    How Do You Write the Reaction Quotient Qc for This Reaction?

    Can't figure this one out. Here's the problem. Solid molybdenum (VI) oxide reacts with gaseous xenon difluoride to form liquid molybdenum(VI) fluoride, xenon gas, and oxygen gas. Write the Qc for this reaction. I know Qc is products over reactants and pure liquids and solids are not...
  32. P

    Calculating Mass from Chemical Reaction

    Homework Statement what is the mass of alum that can be prepared from 1.340g of Al. Homework Equations 2Al+2KOH+4H2SO4+22H2O ---> 3H2 + 2KAl(SO4)2 * 12H2O The Attempt at a Solution given Al is the limiting reagent. Find the moles of Al using n=m/M I find Al moles to be...
  33. P

    Reaction between photon and proton

    A high energy proton can collide with a photon to produce a charged pion and a neutron. If the photon comes from the cosmic microwave background and has an energy equivalent to a temperature of 3 K, what is the minimum energy of the proton in eV necessary to allow this reaction? I'm thinking...
  34. M

    Structural Forces and Unknowns: Solving for Reaction Forces in a Complex System

    My problem here seems that I can't figure out how to solve for my unknowns. I have 3 equations for force, and I'm not sure if that equation I have for the moment around the origin counts as 3 new independent equations if I split them up into i, j, and k components. If that is allowed, then I...
  35. M

    How Do You Determine the Direction of Reaction Forces in Structural Problems?

    Homework Statement Problem 4.36 http://xps2pdf.co.uk/4c82ad8dcb91d5507169e0a18804ea30bf81d592/4.36.pdf Homework Equations The Attempt at a Solution I am not sure if I am doing this correctly..there is a lot of information that I am not using to solve the problem (i.e. all the different...
  36. Magna Visus

    What factors affect the reaction time of a long bar?

    Hello guys, The title might be slightly misleading, it's not related to general physics. It's a hypothetical question that's far from being realistic of practical; Suppose you have a very very long bar, and suppose it's layed on a type of material with no friction, a person stands at the 1st...
  37. T

    Heat of Reaction: Why is dN not Included?

    Hi! In most textbooks on chemical physics/thermodymanics it is said that under fixed pressure the heat of reaction equals change of enthalpy of the system since dU = \delta Q - p\cdot dV, and hence d(U+pV) = \delta Q. But my question is: why they do not write a term +\mu\cdot dN which describes...
  38. R

    Atom and its reaction while travelling in a magnetic field

    Hello I was reading a book about quantum mechanics and in some point it used as an example the reaction of the atom while its traveling through a magnetic field . So the author described an atom as a magnetic arrow ( which isn't complety right but he did that so he can reveal the truth...
  39. PhizKid

    How to find the net ionic reaction with only reactants/reagents?

    For example, if I am given something like HCl and NaOH, or ##HNO_3## and ##Ba(OH)_2##. Can someone explain how I would find the net ionic reaction or provide a link to a good tutorial on how to write the equation for the total/net reaction with only the reagents/reactants?
  40. Pythagorean

    Carbonation sensation is a chemical reaction, not physical

    But can be modulated by bubbles. PLOS ONE: The Influence of Bubbles on the Perception Carbonation Bite
  41. jaumzaum

    Substances whose chemical reaction is easily perceptiple

    I was trying to solve the following exercise: Choose the option that has the pair of substances whose chemical reaction is easily perceptiple a)Br2(aq) + NaCl(aq) b) Cl2(aq) + NaI(aq) c) H2(g) + MgSO4(aq) d) Ag(c) + ZnSO4(aq) e) HCl(aq) + Cu(c) I would say if the salt was an alkali...
  42. K

    Difference between Reaction Rate and Rate Law?

    Lets say you have the reaction aA + bB => cC + dD The rate of the reaction is given by the change in initial concentration over the change in time. -\frac{\Delta \left[ A \right]}{a\Delta T}\; =\; -\frac{\Delta \left[ B \right]}{b\Delta T}\; =\; \frac{\Delta \left[ \mbox{C} \right]}{c\Delta...
  43. C

    Why Does My Pendulum Pin Support Reaction Calculation Differ from 299N?

    I've got a similar question to http://www.chegg.com/homework-help/questions-and-answers/pendulum-consists-10-kg-uniform-slender-rod-15-kg-sphere-pendulum-subjected-torque-m-50-n--q2722886 for homework. I applied the same steps I used on my homework question to this problem and I get a different...
  44. C

    What Happens When Helium and Anti-Hydrogen Interact?

    Hi, As I understand it, if you have a piece of matter (hydrogen) and a piece of antimatter (anti-hydrogen) and they interact with each other they annihilate. What if your matter was Helium and your "antimatter" was anti-hydrogen? or the other way around what if your antimatter was antihelium...
  45. P

    What is the Product of OH- and CH3NH2 Reaction?

    Homework Statement The question is what is the product of OH\cdot and CH3NH2 The correct answer is H2O and \cdotCH2NH2 Homework Equations The Attempt at a Solution The correct answer makes sense, but I don't understand the mechanism in terms of nucleophiles and electrophiles. If...
  46. P

    Finding the reaction force - moments and equilibrium

    The problem statement A uniform rod of length 2m and mass 5kg is connected to a vertical wall by a smooth hinge at A and a wire CB as shown. If a 10 Kg mass is attached to D, find: a) the tension in the wire b) the magnitude of the reaction at the hinge A. attached is my copy of the...
  47. D

    Interpreting buffer solution reaction

    So it seems I've been seeing two different ways of interpreting buffer solution reactions. One to me seems to work with Le Chatelier's Principle and the other doesn't. I am dropping a strong base, NaOH, into a weak acid/base buffer solution. View A: HA + H2O <--> (H3O+) + (A-) Reasoning: The...
  48. B

    Wheels Reaction Forces: Solving for Ra and Rb?

    Homework Statement In the diagram below, work out the reaction force in each of the wheels. Note there are two wheels that make up Ra. The Attempt at a Solution 0 = 25,000*2 + 5,000*15 -5 Rb - 8,000*2 0 = 50,000 + 75,000 - 5 Rb - 16,000 0 = 109,000 - 5 Rb 5 Rb = 109,000 Rb...
  49. Astrum

    Elemental iodine from Potassium Iodide - Reaction Equations

    In the reaction to get I2 from an aqueous solution of KI. The process. Take the aqeuous KI, and pour concentrated hydrochloric acid, followed by hydrogen peroxide. K++I-+H++Cl-+H2O\rightarrow KCl + HI + H2O The reaction with H2O2 is perplexing. I'm a physics student trying to do...
  50. T

    A fatal chemical Reaction for TV Series

    I am currently in the process of re-writing an episode for a Science Fiction television series. I have two problems. A scene at a Japanese Naval Base where I need to inflict mass casualty thru a chemical reaction that will affect only the area of the naval base itself, and wipe out all the...
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