Equilibrium Definition and 1000 Threads

  1. patrickbotros

    Equilibrium Problem: Relationship Between Q, K, and ∆G

    I just took a test today, and I want to see if I got the right answer. I sort of guessed. Here's the question: Which statement is correct? a) When Q<K, then ∆G=1 b) When Q<K, then ∆G=-∆S c) When Q=K, then ∆G=0 d) When Q>K, then ∆G=1 e) When Q>K, then ∆G=-RT I put C, because when Q=K, the...
  2. patrickbotros

    When to use which Equilibrium Constant. (Kp vs. Kc)

    Hello forum! My name's Patrick, and I'm taking Chemistry 212. We're learning about equilibrium and I'm constantly getting K's confused. For example: In the equation ΔG=-RT*ln(K), I have no clue whether to use the Kp value or the Kc value. Could I have used either? I just need a very thorough...
  3. It's me

    Callen Thermodynamics 2.8-2 matter flow equilibrium

    Homework Statement A two component gaseous system has a fundamental equation of the form $$S=AU^{1/3} V^{1/3} N^{1/3} + \frac{BN_1N_2}{N}$$ where $$N=N_1+N_2$$ and A and B are positive constants. A closed cylinder of total volume 2V_0 is separated into two equal subvolumes by a rigid diathermal...
  4. X

    Why does the potential difference between two capacitors seek equilibrium?

    Suppose we have a circuit with two capacitors connected to each other, C1 and C2. C1 is charged and has a potential difference of 5 V (V1=5V), but C2 is not charged (V2=0) Apparently it is known that the potential difference of these two capacitors will want to reach equilibrium. So V1=V2...
  5. P

    Equilibrium of Beams: Understanding Forces and Reactions

    hello! I don't understand, what is the equation that we use in beams is it that forces 1,2,3 equal with the reactions at the two supporting points? or the torques are 1,2,3 equal with the reactions at the two supporting points? and how do we find the reactions at the supporting points? thanks!
  6. hdp12

    Problem Check: Equilibrium of Particles

    Homework Statement A continuous cable of total length 4 m is wrapped around the small pulleys at A, B, C, D. If each spring is stretched 300 mm, determine the mass m of each block. Neglect the weight of the pulleys and cords. The springs are unstretched when d=2 m. The Attempt at a Solution I...
  7. K

    Explanation of Iodine Equilibrium in immiscible solvents

    Homework Statement I'm studying the equilibrium of I2 and its distribution in two immiscible liquids (varsol and aqueous potassium iodide). Since I2 is non polar; it will "prefer" to be in varsol but since KI (aq) is an ionic salt solution, iodine will also dissolve to give the I3- ion. When...
  8. R

    Balancing two rollers on a hill

    Homework Statement Two rollers, of masses 2kg and 3kg, are connected over a pulley by a massless string. They rest in equilibrium on two inclined slopes, as shown in the diagram to the left. Friction is negligible. What is the distance X? Homework Equations Fg = mg Component of Fg parallel to...
  9. S

    Shielding simulation and nuclide vector

    I have to make a shielding calculation of some radioactive scrap metal in a cask, using Geant4 (hence Monte-Carlo). I will be given a nuclide vector and I'll have to calculate the ambient dose equivalent rate outside of the cask. The nuclide vector I will be given will be something like: Co60...
  10. A

    Pressure/Temperature mechanical equilibrium

    1. Homework Statement Three thermally insulated containers of equal volume are connected together by thin tubes of negligible volume so that gas can flow from one container to the next when a valve between them is open. Initially, the pressure and temperature in each container is at the same...
  11. B

    Equilibrium expressions and partial pressures

    Homework Statement In considering the reaction: 3NO (g) + H2O (l) → 2HNO3 (aq) + NO (g) student A writes the equilibrium expression as: K=[NO][HNO3]2/[NO2]3 while student B writes: K=PNO [HNO3]2/[NO2]3 Whose equation is correct? Homework Equations NA The Attempt at a Solution This is a...
  12. B

    Is the System at Equilibrium with Given Concentrations?

    Homework Statement Consider the following reaction: H2 + I2 → 2HI (all gases) At 740 K, this reaction has an equilibrium constant of 50. If, at 740 K, the concentration of hydrogen gas is 2 M, iodine gas is 3 M, and hydrogen iodide gas is 6 M: (A) the concentration of hydrogen iodide will...
  13. hdp12

    Equilibrium of a Particle: Determining Forces in Cables and F for a 4-kg Lamp

    Homework Statement I am stuck on this problem for my mechanics class. Please help me. Determine the force in each cable and the force F needed to hold the 4-kg lamp in the position shown. Hint: First analyze the equilibrium at B; then, using the result for the force in BC, analyze the...
  14. hdp12

    What is the weight of block D in this equilibrium of particles problem?

    Homework Statement Here is the problem that I am stuck on in my mechanics class. https://lh4.googleusercontent.com/ygXVjNfI4iP8xVpEjhxXZlWlDqg_VrM2gCVFLyomOVwWCfcLU78mIcPEc7hEzUqBoACIiQ=w1210-h506 Homework Equations F=-kx The Attempt at a Solution See the attached picture of my work...
  15. terryds

    Triangle Ladder equilibrium problem

    Homework Statement http://www.sumoware.com/images/temp/xzebnqpmgdnohmgo.png An isosceles-triangle-shaped ladder like the picture above, has a negligible mass. A man with mass m kg climb the ladder till the height is 3 meter (see picture above). Determine the tension of the link (at...
  16. M

    MHB Equilibrium Problem: Landscaping Business|Accounts & Maintaining 500

    I own a landscaping business with accounts paying regularly. If I add 5 new accounts a week and on average an account stays a customer for one year before quitting, what would my equilibrium number of accounts be? How long to reach equilibrium? how many do I need to add per week to maintain at a...
  17. T

    Finding angle required for equilibrium on a slope

    Homework Statement A heavy uniform cylindrical drum is placed, with its axis horizontal, on a slope inclined at an angle α to the horizontal. It is prevented from sliding or rolling down the slope by a triangular wedge. The weight of the wedge is negligible compared with the weight of the drum...
  18. ChrisVer

    Equilibrium at Universe (possible?)

    How can Universe be at equilibrium when the FRW metric has no time-like Killing Vector?Request: Please, move this into Cosmology thread... :( Mistakenly I posted it in HEP
  19. C

    Finding Equilibrium in a Three-Pulley System

    Homework Statement Place 0.150kg (including the mass of the hanger) at a position somewhere between 0 degrees and 90 degrees. (I chose 45 degrees for this problem.) Place the second pulley at exactly 180 degrees and the third pulley at exactly 270 degrees. Determine how much mass you must place...
  20. K

    Chemical Equilibrium and Le Chatelier's Principle

    Homework Statement Without adding any Chromium based compounds, how would you manipulate the above equation to produce more CrO42- ions? Be sure to use chemical equations to show the answer. Homework Equations 2CrO42- (aq) + 2H3O+ <--> Cr2O72-(aq) + 3H2O (l) The Attempt at a Solution So my...
  21. little neutrino

    Gravitation - Position of Stable Equilibrium

    Homework Statement A particle of mass 3m is located 1.00 m from a particle of mass m. You put a third mass M so that the net gravitational force on M due to the two masses is exactly zero. Is the equilibrium of M at this point stable or unstable for points along the line passing through M and...
  22. J

    Cylinder Equilibrium (2012 F = ma #12)

    Homework Statement The problem is #12 found here: https://www.aapt.org/physicsteam/2013/upload/exam1-2012-unlocked-solutions.pdf. A uniform cylinder of radius a originally has a weight of 80 N. After an off-axis cylinder hole at 2a/5 was drilled through it, it weighs 65 N. The axes of the two...
  23. Tyrannosaurus_

    Interpret results of suspended mass / tension problem please

    Homework Statement Two masses: m1 = 45 kg, m2 = 12kg. m1 (45kg) sits at rest on a table top with static friction co. 0.45, kinetic friction co. 0.35. m2 is suspended in the air. m2 is attached to m1 by a massless wire hung over a frictionless pulley Homework Equations FBDs, net force...
  24. C

    Equilibrium Force: Solving for Centre of Mass | Homework Statement

    Homework Statement Homework EquationsThe Attempt at a Solution I'm not sure about which topic it is asked. I think it's something about the centre of mass . Because the statement " The pole and the box do not change form" . The answer is (1 + tan Θ)/(1 - tan Θ)
  25. G

    Equilibrium modelling in kraft mills

    Hi, I've been working with equilibrium modelling in bleach plants of kraft mills in order to find areas likely of being subjected to mineral scale deposits. This has been rather successful - and it's been done successfully be many people before me. However, now I am interested in applying...
  26. Shindo

    Question on thermal equilibrium?

    So I'm not too sure about the answer to this question: explain why it is advisable to add water to an overheated automobile engine only slowly, and only with the engine running? So if something is overheating, it makes sense to want to cool it. Since the water's temperature is less than that...
  27. B

    Finding the Center of Mass of a Suspended Scaffold and Paint Cans System

    Homework Statement A horizontal scaffold, of length 2.00 m and uniform mass 50.0 kg, is suspended from a building by two cables. The scaffold has dozens of paint cans stacked on it at various points. The total mass of the paint cans is 80.0 kg. The tension in the cable at the right is 830 N...
  28. S

    Kinetic equilibrium of chemical reaction

    I was thinking about this: Let's consider a dissociation of some chemical that can run in both directions: AB\rightleftharpoons A^{+}+B^{-} Dissociated form is soluble in a solvent and undissociated form is not - it precipitates. Then the reaction proceeds to the left much faster than to the...
  29. gracy

    Chromate and dichromate ions in equilibrium

    Homework Statement :-Why in equilibrium equation of potassium dichromate and chromate give below (in point 2.Relevant equations )there is H2O with dichromate ion but not with chromate ion, rather 2 hydrogen cation is present?[/B]Homework Equations [/B]The Attempt at a Solution :-I think it is...
  30. D

    Boltzmann equation for the early Universe

    I'm currently reading about the Boltzmann equation, used for the early Universe. The equation I end up with, after some simplifications is the following: \begin{equation} a^{-3}\frac{d}{dt}\left(n_1a^3\right) = n_1^{(0)}n_2^{(0)}\langle\sigma v\rangle\left[\frac{n_3 n_4}{n_3^{(0)}n_4^{(0)}} -...
  31. M

    Is the Equilibrium Calculation for HI Correct?

    Kc1 = (5.8*2/5)^2 / (14/5)(1.4/5) = 6.865 6.865 = [HI]^2 / (45/253.8/100)(0.5/2/100) [HI] = 5.52x10^-3 M mass no of HI = [HI] x (126.9+1) x 100 = 70.6g is it correct? And how to do 3bii I GOT 3bi Kc2 = [HCl(g)]^2/ / Kc(1) [H2(g)] [Cl2(g)]
  32. nmsurobert

    Thermal Equilibrium: Why Does Car Get Hotter Inside?

    So you take some boiling water and drop a metal cube into it and the cube will reach the temp of the water. Or you leave some hot water out on a desk and the water will eventually become room temperature, right? Then why, in the summer time, does the inside of the car get way hotter than the...
  33. M

    Buffer solution + equilibrium + Organic compound

    For this question,why Ka =(ch3coo-)(h+)/(ch3cooh) instead of Ka =(ch3coo +x)(x)/(ch3cooh-x) ?
  34. B

    Torque seesaw problem- rotational equilibrium

    Homework Statement A seesaw with a mass of 5 kg has one block of mass 10 kg two meters to the left of the fulcrum and another block 0.5 m to the right of the fulcrum. If the seesaw is in equilibrium, A. find the mass of the second block. B. find the force exerted by the fulcrum I have trouble...
  35. S

    Static Equilibrium: Homework Questions

    Homework Statement I have a question about the following question: Firstly, shouldn't there be a normal force for each hand (part a), but here they treat it as one normal force. Also in part b, why isn't the torque for Fn1h = 0? Since that is the pivot point, isn't the moment arm zero?
  36. M

    Electrostatic equilibrium, deflection of a cobweb

    Homework Statement Homework Equations After creating a FBD and analyzing the forces, I get the equation for the angle as ## tan \theta = \frac{k q^2}{m g r^2} ## The Attempt at a Solution [/B] I have tried to find a way to find the distance between the charges ## r ##, but the only way I...
  37. C

    How Much Load Can a 300-kg Beam Support Before Exceeding Strut Safety Limits?

    Homework Statement A uniform 300-kg, 6.0 M long, freely pivoted at P, as shown in the figure. The beam is supported in a horizontal position by a light strut, 5.0 M long, which is freely pivoted at Q and is loosely pinned to the beam at R. A load of mass is suspended from the end of the beam at...
  38. W

    Pendulum Equilibrium: Can It Pass Balance Point Twice?

    Consider a pendulum in it's balance point hanging from ceiling. It can swing in all the directions in the space. The pendulum can only swing in a sphere(the string can't bend). Now, is it possible to release the pendulum in a particular height and with a initial condition that in the first...
  39. O

    Block on moving wedge (Maximum force for equilibrium problem

    Homework Statement Given: The friction between the block with mass 11kg and the wedge with mass 22kg is 0.48. The surface between the wedge with mass 22kg and the horizontal plane is smooth (without friction). The [A][/g] = 9.8m/[/2]. A Block is released on the incline plane (top side of...
  40. M

    Heat Capacity and Thermal Equilibrium

    Homework Statement A 3.50-kg block of iron initially at 8.00 × 10^2 K is placed on top of a 6.25-kg block of copper initially at 4.00 × 10^2 K. Assume the blocks are thermally insulated from their surroundings but not from each other and that they constitute a closed system. How much energy is...
  41. nomadreid

    Game theory -- Nash equilibrium

    Suppose we have a game, played in which Alice and Bob play mixed strategies: (sorry for the dots, but I don't know how to put a table or tab spacing in this text box) ..............Bob ..........Dove, prob q......Hawk, prob (1-q) ...Dove , prob p......(2,3).........(4,5) Alice ...Hawk, prob...
  42. N

    How Does Child Movement Affect Torque and Force Distribution on a Plank?

    Homework Statement A child of mass m is supported on a light plank by his parents, who exert the forces F1 and F2 as indicated. Find the forces required to keep the plank in static equilibrium. Use the right end of the planks as the axis of rotation. ( Answer: F1=(1/4)mg, F2=(3/4)mg )...
  43. M

    Temperature of gas and solid in thermal equilibrium

    Hello I got to thinking about temperature when i prepared a lecture for my high school class. For a monoatomic ideal gas the temperature is proportional with the average kinetic energy of the atoms. For a diatomc gas we also have rotational energy (vibrations assumed to be freezed out), and for...
  44. A

    Calculate CO2 for Water Equilibrium at pH 7.2

    Hi, I must calculate how much CO2 has to be removed from the water (pHs=7.2) to obtain equilibrium Given concentrations: HCO3-: 223 mg/L CO2: 60 mg/L pH: unknown SI: unknown What is meant by equilibrium? (ph=7?) Please advise how to tackle this problem
  45. E

    Equilibrium of a Particle: Finding the Unstretched Length of a Spring

    Homework Statement The question are included in the picture that are uploaded. So i know that for these systems to be at equilibrium, the net force in the x and y-axis must equal to zero. I wanted to write in the question and the diagram but i don't know how else to put it. Homework Equations...
  46. M

    Finding Equilibrium concentrations with added solutes?

    HF(aq) ↔ H+ + F- Determine equilibirum concentrations with Initital concentrations and Kc. Kc = 7.2 x 10-4 [HF] = 1.00M [NaF] = 0.50M I understand how to do an ICE table and put together questions, but what do you do with [NaF] when it is not part of the chemical equation? How to I factor it...
  47. P

    Why catalysts affect forward and reverse reactions?

    Based on the very basic understanding on enzymes I have gained from Year 12 Biology and Chemistry, I don't undesrtand why the enzymes specific shape also helps the reverse reaction. I guess my trouble would be due to the simplified diagrams I've seen from Biology, where only the forward reaction...
  48. W

    Hydropower plant in equilibrium

    I am trying to set up an equation relating the mechanical energy in a hydropower plant to its electrical output. What I picture is the relation between the energy input from the moving water, to the rotational energy of the turbine to the electric output of the generator. I know I can calculate...
  49. C

    Find load to create equilibrium on a bar.

    Homework Statement A 6.0 m bar is supported by a fulcrum at 3.9 m from the left end. There are loads applied to each end of the bar. The load at the left end of the bar is 468 N. What load in Newton should be applied to the right end of the bar to create equilibrium? Homework Equations M=Fd...
  50. P

    Two beams hanging in equilibrium

    Homework Statement Two identical, uniform beams weighing 260 N each are connected at one end by a friction-less hinge. A light horizontal crossbar attached at the midpoints of the beams maintains an angle of 53 degrees between the beams. The beams are suspended from the ceiling by vertical...
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