Reaction Definition and 1000 Threads

  1. B

    B What is the reaction to gravity's pull in a vacuum?

    I am trying to understand something. Let me pitch a scenario: You have two asteroids in a vacuum. Each is large enough to be round by gravity. They are separated by roughly the distance from the Earth to the moon. Relative to each other, they are moving at 0 in all directions (aka, they are...
  2. C

    Can Non-Spontaneous Reactions Occur When Coupled with Exergonic Reactions?

    Greetings everyone! I have been a long-time lurker on here and have just recently signed up. I'm unsure if this was the correct forum to post this in, so I apologize in advance. My question isn't exactly homework per se - I am currently studying for my MCAT and have been trying to wrap my head...
  3. D

    Why In Struvite formation HPO42- is favored over PO43-?

    Cheers community, I have been studying the Struvite formation from respective ions. Being the general formula for Struvite MgNH4PO4.6H2O I intuitively tought the reaction would be Mg2+ + NH4+ + PO43- + 6H2O↔ MgNH4PO4.6H2O. However from literature and from practice, not only the optimal pH seems...
  4. caters

    Chemical water treatment: Acid base reaction

    I was thinking of a hypothetical waste system that uses nanotechnology to its advantage. At the individual level, waste just passes through into pipes when flushed like it normally does. But once it reaches the water treatment plant there is an initial filter to catch solid waste(in other...
  5. M

    MHB Oxidation-Reduction in 2Ca + O2 -> 2CaO Reaction

    can some one show me by looking at electrons lost and gained which is oxidised and reduced in the reaction 2ca+o2->2cao i would of said each calcium atom has a O.N of +2 and o2 has a O.N of 0 the o in 2cao has a O.N of -2 so that means the ca has a O.N of +2. but that makes no sense. where...
  6. D

    B Understanding Newton's Third Law: Investigating the Equation F=Rv(m1m2/l^2)

    Hello, buddies! I read a piece of text, where I found a puzzling interpretation of Newton's third law (F1=-F2). The author gives the following representation: F=Rv(m1m2/l^2) R - reaction; m1, m2 - masses; v - velocity of reaction; l - distance between the two objects. Please, help me with...
  7. J

    Concentration of a salt produced by neutralization reaction

    Homework Statement 10.00 cm3 of 1.00 mol dm–3 sulfuric acid is fully neutralized by 20.00 cm3 of 1.00 mol dm–3 of sodium hydroxide. What is the concentration, in mol dm–3, of sodium sulfate solution produced by the reaction? A 0.33 B 0.50 C 0.67 D 1.00 Correct answer = A Homework Equations...
  8. O

    Reaction force be 0 at top of circular path swing?

    Homework Statement Hi, I have a question about a bucket filled with water being swung in a vertical circular path. I'm wondering why at the top of this swing, the reaction force of the bucket on the water can be 0? (ie. why is the minimum centripetal force required only the weight of the...
  9. G

    Entropy change when the number of particles decreases

    Hi. I found following exercise in a high school textbook: "Compute the entropy change in following process:" The solution is "The number of particles decreases from ##N_1## to ##N_2=N_1/2##. Hence the entropy decreases by $$\Delta S=-k\cdot N_1\cdot \ln{2}\enspace ."$$ I can't quite follow...
  10. shihab-kol

    What Makes Light Energy Essential in the AgBr → Ag + Br2 Reaction?

    AgBr →Ag + Br2 This reaction takes place in presence of light energy, but why only light ?? Why not electricity, heat or any other forms of energy?
  11. O

    I Reaction Q value and threshold energy

    In order to calculate the energy of a reaction's ejectile, we make use of the concepts of the conservation of energy and momentum along with the reaction Q energy. However, if there is a threshold energy with above zero, meaning Q value is negative, do we have to consider the threshold energy as...
  12. Z

    Calculate reaction heat from quantum mechanics

    Homework Statement I have some doubts about the method constructing chemical reaction process of quantum mechanics in the referencehttp://www.southampton.ac.uk/assets/centresresearch/documents/compchem/DFT_L2.pdf, for the example of ##H_2O## molecular dissociation to ##H^+## and ##OH^-## ions...
  13. herbertpbarreto

    Chemical Reaction Engineering homework

    Homework Statement The decomposition of phosphine 4PH3(g) + P4(g) + 6H2(g) is first-order with respect to phosphine with a rate constant k = 0.0155 s-l at 953 K. If the decomposition occurs in a constant-volume batch reactor at 953 K, calculate, for 40% conversion of PH3, (a) the time...
  14. E

    Find product kinetic energies in (α,γ) reaction

    Homework Statement 5.5 MeV alphas hit Be-9 and produce carbon with a gamma. the Q value is 10.65 I have to find the kinetic energy of the carbon nucleus and the gamma and I am to ignore the gamma ray momentum. Homework Equations T = p^2 / 2*m Q = T_be + T_alpha - T_c - T_gam[/B]The Attempt...
  15. S

    Duration of Equilibrium Reaction

    I am wondering the answer to the following question, and what equation you would use to solve it: What is the duration of the following reversible reaction? A <--> B You have 10 moles of A and zero moles of B. After 1 minute, 25% of A turns into B, and 50% of B turns into A. My class...
  16. T

    Effect of Temperature on Chemical Reaction Equilibrium

    here is the question (part I): For part I, I need some assistance, I cannot figure out how to do the question. I know eventually what to do, it's just working out the equilibrium constants I'm having trouble with. So to start, I want to work out the K values at 600K and 800K, I do this by...
  17. D

    How to Obtain Reaction of Truss Pinned Connection A, B, and C?

    Hey guys, Sorry for this newbie question, I would to ask how to I obtain the reaction of the pinned connection of A, B, and C (See attachment)? Do I really have to use Force-Method? I actually attempted to use Moment at different places and do simultaneously (Idk if it's the right thing to do)...
  18. S

    Finding magnitude and direction of reaction force

    Homework Statement A uniform horizontal rod of mass 4 kg and length 500 mm, is hinged at the left hand side and supported at rest by a chain (S) attached 10 cm from the hinge. Calculate the magnitude and direction of the reaction force on the rod at the hinge. State the principle you have...
  19. T

    Approaching Reaction Feasibility: Thermodynamics and Equilibrium Constant

    How would one approach part I and II? In terms of thermodynamics I'm not sure how I can show that this hypothesis is true. Could I work out the equilibrium constant and make a decision based on its magnitude? For example if it is >>> 1 then the hypothesis is true, would that be correct? For the...
  20. Sebastiaan

    I Anti Proton - Non Proton reaction

    Alright, I have a basic understanding about anti hydrogen - hydrogen annihilation reaction. But what exactly happens if an anti hydrogen atom stumbles into anything else like a deuterium, tritium of helium atom? From my limited understanding, antimatter can only react with its anti-particle...
  21. Ryaners

    Finding order of reaction & rate constant

    I'm trying to solve one of the problems in my textbook (Atkins Physical Chemistry) and I just can't get it out. Here's the problem: "The data below apply to the formation of urea from ammonium cyanate. Initially 22.9g of ammonium cyanate was dissolved in enough water to prepare 1.00 dm3 of...
  22. A

    B Will there be a reaction at the hinge B in this question?

    I have solved this question by completely disregarding the reaction at the hinge B. And surprisingly, answer turns out to be correct. Why is that so?
  23. allanwinters

    Energy changes and rates of reaction

    Homework Statement The complete combustion of methane is represented in the following equation: CH4(g) + 2O2 -> CO2(g) +2H2O(g) +802.5 kJ Assume that natural gas is essentially methane. The emission level of Carbon monoxide, CO(g) from the burning of natural gas is 19.14kg/MJ of energy...
  24. spareine

    B How to pronounce a nuclear reaction written in AZE notation?

    Pronouncing a nuclear reaction like as "one,zero,neutron + 235,92,uranium yields 141,56,barium + 92,36,krypton + 3,1,0,neutron" is awkward. How is it pronounced by physicists in practice?
  25. G

    Skier, curved motion on slope/ reaction force?

    Hi folks, I was thinking about an old physics olympiad question I read. Can't remember exactly but it was about minimising the reaction force of a skier as she took a curved path down a ski-slope. That got me thinking generally about what is going on with the reaction force in such a situation...
  26. N

    Average Reaction Rates Homework: Δ[A]/aΔt = Δ[ B]/bΔt

    Homework Statement Homework Equations Δ[A]/aΔt = Δ[ B]/bΔt The Attempt at a Solution Δ[ I]/3Δt = Δ[H]/2Δt = 7.8E-4. What exactly am I supposed to do for this?
  27. W

    B Actual value of normal reaction

    I am a high school student in Hong Kong studying Physics. I am having some problems about atmospheric pressure. Imagine there is a cube block with volume 1 m3 and top surface area 1 m2 . The cube block is being placed on the floor and it has mass of 1 kg. What is the normal reaction force F...
  28. Magnetic Boy

    Energy of neutron in fission reaction

    Homework Statement when fission occurs why neutron get less energy as compare to the daughter nuclei? i need both physical and mathematical explanation. Homework EquationsThe Attempt at a Solution i think it is due to the small mass of neutron. but i am not sure as it is not satisfactory. a...
  29. Jasiu

    I Fusion reaction deuteron + tritium

    Hello. Where is come from the heat (about 17,59MeV) from reaction deuteron + tritium -> Alfa + netron + Q although sum of substrates's mass is greater than sum of products's mass?
  30. Thermo

    How to Determine Reaction Kinetics and Conversion Rates for Ammonia Synthesis?

    I need to design an ammonia production process but I can't find the kinetic info from the articles online. The catalyst will be iron. Can somebody explain how to find kinetics data and conversion rate? I found some articles but there was no conversion info on them.
  31. T

    Static friction being the force that opposes the reaction

    Hi there, I was thinking that static friction works in opposition to a reaction force like the force of a fridge against you as you push it. However, since you are pushing horizontally and friction works against you why is it equal or greater than the reaction force? Will the force get...
  32. I

    Enthelpy change of a neutralisation reaction

    Homework Statement Given the reaction K2CO3(s) + 2HCl(aq) → 2KCl(aq) + CO2(g) + H2O(l), I need to find the enthalpy change in J, given that: The specific heat capacity of water is 4.2J g-1 °C-1, and The mass change of potassium carbonate is 2.98g, and the temperature change was °6C, and the...
  33. Lacplesis

    Prompt neutrons, delayed neutrons, chain reaction control

    Hello, I am reading about this and I have a question , so let me explain how I understood this and please correct where I am wrong. I will ask about nuclear reactors because obviously in bombs only prompt neutrons matter since there is no need for any control only an exponential increase in...
  34. H

    Question regarding fusion reaction containment and procedure

    Good evening, I am new to this forum and do not have a strong physics background. So if my questions seem woefully inept please respond with a simple laymans answer. I understand that there are 2 basic ideas for fusion containment, and that the main 2 components of any successful fusion...
  35. grapheeene

    Modeling Surface Reaction (CVD) on ANSYS Fluent

    Hi guys, First of all, thank you for your help. I am new in Ansys and Fluent (less than a month), hoping to learn. I am trying to model a simple and single surface reaction CH4 (g) -> C(s) + 2H2 (g) on a "CVD reactor" to grow C(s) (graphene, or graphite). The inlets are gases inyections of...
  36. Kaneki123

    Half-Reactions in Zn + HCl Reaction

    I do not have a clear concept about half-reactions...Can someone please give the half reactions for following reaction, Zn^0 + 2H^1 Cl^-1 -----> Zn^+2 Cl2^-1 + H2^0 or Zn + HCl ----> ZnCl2 + H2
  37. M

    B Can Classical Forces Explain Nuclear Fission and Fusion Reactions?

    good morning, I'd like to know if exsists a classical explanation and, of course, qualitative about the nuclear fission / fusion reactions. I would like to explain the development of external energy to considering only nuclear forces system in terms of internal mechanical energy and the fact...
  38. G

    Splitting reaction into horizontal and vertical components

    Homework Statement In each of the diagrams (please see attached file (I am sorry for the rotated, the original was in normal form but when uploading it, it was somehow rotated)) and the description of each case below, a particle is moving on a smooth surface, so that the reaction force R acting...
  39. F

    Why is Only One Reaction Shown at the Pinned Support?

    Homework Statement The modulus of elasticity of each member is E = 20kN/(mm^2) and the cross section of each member is 1000(mm^2) , except member EB and EC is 40(mm^2) , determine : a) The vertical displacement at joint C b) The horizontal dispalcemnet at joint C at A , it's a pinned...
  40. L

    How to write equations for salt dissolving in water/ionizing

    Homework Statement Write separate equations for each potassium salt (KH2PO4) dissolving in water and for the ionization reaction of the weak acid anion that each of these salts contains. Homework Equations None The Attempt at a Solution I just needed to clarify when it dissolves in water do...
  41. Clara Chung

    B Action and reaction of a rocket in space.

    By conversation of momentum, the rocket can be propelled forward by ejecting mass like gas. However, how is the propelling force explained in terms of action and reaction? If gas is ejected, what does the force act on?
  42. N

    Rod is toppling. Find reaction force as a function of theta

    Homework Statement Rod of length b and mass m topples from vertical position at theta = 0. Calculate the reaction force f as a function of theta. What is the minimal and maximal values of f for theta between 0 and pi Homework Equations Third law?[/B]The Attempt at a Solution I never really...
  43. R

    Model reaction diffusion brusselator 2d matlab

    Hello, I have a project (model reaction diffusion brusselator 2d) ∂u/∂t=A+u^2v-(B−1)u+D1((∂^2)u/∂(x^2)+(∂^2)u/∂(y^2)) ∂v/∂t=Bu−u^2v+D2((∂^2)v/∂(x^2)+(∂^2)v/∂(y^2)) initial conditions: u(x,y,0) = 0.5 + y, v(x,y,0) = 1 + 5x. boundary conditions: ∂u/∂n = 0, ∂v/∂t = 0 n-external normal to the...
  44. Evangeline101

    How Do You Propose a Reaction Mechanism for a Multi-Step Reaction?

    1. Homework Statement 2. Homework Equations rate law equation 3. The Attempt at a Solution a) I would expect this reaction to be a multi-step reaction because there are six reactant molecules, as shown in the overall chemical equation. For this reaction to be one-step, all six molecules...
  45. I

    Nuclear reactions, cross section, reaction rate

    Homework Statement A beam of ##^{50}##Ti nuclei impinged on a ##0.5 mg/cm^2## thick ##^{208}##Pb target in an experiment lasting 176 hours. During that time a total of ##3260 \; ^{257}##Rf nuclei were detected. The beam intensity was throughout the experiment constant at ##6.6\mu A##. Each...
  46. K

    Max reaction force - ferris wheel

    Homework Statement What is the maximum reaction force exerted by a seat on the passenger of a ferris wheel? There's a diagram showing the seat at 6 o'clock, 12, 3, and 4:30... on a 12 hour clock. Homework Equations N/A The Attempt at a Solution I guess the reaction force is the normal force...
  47. J

    Upthrust Reaction - Water Injection @ 5bar -8msw Subsea

    Hello, I have a problem Basically, in theory -- a damaged 1220mm dia pipeline sub-sea (-8msw) with a 500mm hole in the 12oclock position 600mm. Pipeline resting on the seabed The goal of the problem is to flush the pipeline of its contents in both directions. The idea - have a containment...
  48. A

    Calculate ΔHo for the chemical reaction:

    Homework Statement Homework Equations The Attempt at a Solution 2(255) - [(1)(159) + (1)(243)] = +108KJ The answer key says its b) -108KJ. Am i doing something wrong or is the book wrong?
  49. ReidMerrill

    Organic reaction mechanism help -- Looking for resources

    I have an assignment in which I must find a named reaction, the original reference to it, and show what experimental evidence was used to develop the reactions mechanism. So far I've had no luck finding anything. It's hard enough finding the original reference and so far I haven't been able to...
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