Reaction Definition and 1000 Threads

My concept of enthalpy change is that the change is based on limits that approach zero. Something like the heat evolved/absorbed per second (but instead of second its a infinitely small). A+B→C ΔH=100J/mole of A (standard enthalpy change) And as such when the reaction first proceeds the...

Limestone stalactites and stalagmites are formed in caves by the following reaction: Ca2+(aq) + 2HCO3-(aq) --> CaCO3(s) + CO2(g) + H2O(l) . If one mol of CaCO3 forms at 298 K under 1 atm pressure, the reaction performs 2.48 kJ of P - V work, pushing back the atmosphere as the gaseous CO2 forms...

I have two motors(m1 &m2) placed on a vertical position(on the ##y-axis##), that have gears connected to their shafts, and I placed the gears next to one another. Fixing them to move together. I now powered both motors allowing their torques to oppose one another and cancel out each other's...

Please see the attached picture. I'm not sure which hydrogen would be anti-periplanar. Any help would be appreciated. Thanks!

Homework Statement The right angle boom which supports the 230-kg cylinder is supported by three cables and a ball-and-socket joint at O attached to the vertical x-y surface. Determine the reactions at O and the cable tensions. Homework Equations M [/B]= r x F unit vector =...

Homework Statement A certain pyrite ore contains 85% of FeS2 and 15% of inerts. This ore is introduced into a roasting furnace with 20% excess air, in order to oxidize the FeS2 in the reaction: \textrm{FeS}_2 + \frac{11}{4}\textrm{O}_2 \rightarrow \frac{1}{2}\textrm{Fe}_2 \textrm{O}_3 +...

Can someone please explain to me why the answer to the following question is Krypton? A step by step solution would be ideal please! (b)The following reaction occurs in a nuclear reactor: 235U+01n →141Ba+X+301n+202.5MeV (i) Identify the element X. Many thanks! (Question is Q12 b part i...

Hey folks, I created and verified a model with hand calculations, and decided to re-use my same logic.. Which now is giving me false numbers. Was wondering if you guys could help me out. Setup/Verification (See attached Reaction_Forces picture): Body in motion being held down by straps...

I just want to start by saying that I have found many questions very similar to this one using the search bar, but I still don't understand exactly what happens initially in a simple voltaic cell with a salt bridge (Daniel cell). For example, I am trying to figure out what initially happens in...

Homework Statement i was told that the the ascending order of the compound undergo SN1 reaction is C6H5CH(Cl)CH3 < (CH3)3 CCl < C6H5C(CH3)2 Cl... it's a past year question . I am sure tha ans is correct. Can someone explain why? Generally , the most reactive is the compound (CH3)3 CCl , Am i...

Homework Statement I just want to know what reaction occurs when magnesium is inserted into NaCl+H2O2+KOH solution. Homework Equations What happened with each component in that solution ? I would be very grateful if you could help me. The Attempt at a Solution

Alka seltzer contains 1916 mg of NaHCO3 and 1000 mg of citric acid. According to some descriptions of the reaction between alka-seltzer and water and then HCl (in stomach), there is an excess of NaHCO3 in the alka-seltzer in relation to the citric acid and the benefits from alka-seltzer come...

In the late 19th early 20th century, sulfuric acid production was a huge deal, and even today, conversion of SO2 to SO3 (contact process) is something that people take great pains to optimize. But I also see references here on physics forums as well as elsewhere which assert that sulfur dioxide...

Hello, I am analysing a 3D D shaped Incompressible Neo hookean material in contact with a semi cylinder using Ansys 14.5 APDL. The input values provided are C10=2737674.313898 and mass of D shape geometry to be 8 kg/m. I have converted these values into density and Shear Modulus as required in...

Homework Statement The standard free energy of activation of a reaction A is 83.7 kJ/mol at 298K. Reaction B is 10 million times faster at the same temperature. The products of each reaction are 10 kJ/mol more stable than the reactants. (a) What is the standard free energy of activation of...

I think I already know the answer to this, but I can't find an easy reliable source online. Does KP predict reaction direction in the same way as KC? i.e. If KP is greater than 1, the reaction favors the products, and if it is less than 1 it favors the reactants? Or is it just that if KP is...

1. Homework Statement A student was investigating the reaction between sodium thiosulfate solution and dilute hydrochloric acid. As the reaction takes place a precipitate of sulfur forms in the solution and makes the solution change from colourless (and clear) to pale yellow (and opaque). The...

The reaction is shown in the image attached. So the lone pair over O goes into making a bond with C. But why does it create a + over O? A + means the number of protons are one more than electrons, or deficiency of 1 electron. But if the lone pair is used up for making a bond, shouldn't it result...

The question is: The rate equation for the reaction A2 + B2 -> 2C (all gases) is rate = k[A2]2[B2]. If the gaseous reaction misture is compressed to half its original volume, by what factor will the reaction rate change. Assume temperature is constant. My thoughts are that the reaction rate...

this is related to the following thread: https://www.physicsforums.com/threads/gravitys-reaction-force.28395/ (but it doesn't seem to accept more replies so i posted here) my cuestions are: - ¿if gravity depends on mass, how come we define a black hole as an object so massive that photons (mass...

I have a question about this reaction, I don't exactly know what I'm going to get (University coursework question). Reaction C4H10O + CaSO4 + HF --> ?

Why in the Law of Mass Action we raise the concentrations of the reactants to the power of their coefficients according to the stoichiometry of the chemical reaction, while the order of the reaction must be determined experimentally ? I may not understand the difference between them.

It's an easy question, let's consider this reaction: ##N+\nu_e \rightarrow e^{-}+P## Is this reaction possible? If is not, what does violate? (I think is possible because charge is conserved, baryon, lepton and fermion numbers are conserved. But I'm not totally sure)

Hello, I was wondering if someone knew what product/chemical could turn the clear Dettol antibacterial spray fluorescent yellow. I sprayed some Dettol onto a bit of kitchen towel and wiped my tap with it and the Dettol on the kitchen towel instantly turned fluorescent yellow. I tried it again...

Homework Statement The cylinder weighs 200[N] and lies on a rough surface. a rope holds it in place. What's the tension T in the rope and what's the minimal coefficient of friction. Homework Equations Friction: f=μN The Attempt at a Solution All the geometry i have drawn. T balances the...

Homework Statement A beam of 12[kN] is on a smooth floor on one side and on a rough edge on the other. The total length of the beam is 10[m]. What is the reaction on the edge. Homework Equations Moments (torque): F1L1=F2L2 The Attempt at a Solution I drew the forces. the reaction on the floor...

I need help finding the kinetics(rate laws) of this process. I've been searching for close to a week and can't seem to find them. It the carbonylation of ethylene to produce propionic acid(pretty much any variant of the process will do). I have access to my schools publication library so the...

Homework Statement A 12 m long uniform ladder, weighing 285 N, leans against the wall. The foot of the ladder is 6.5 m away from the wall. Determine the reaction components and the resultant reaction(magnitude & direction) if the coefficient of friction for static at the wall and the floor are...

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...

Hi, Can anyone explain me that in chemical kinetics, the rate of reaction can be determined by just determining the rate of any reactant of product involved in the reaction, but how? How the rate of change of concentration of just one specie can tell you about the whole reaction? I found the...

I understand that in a rollercoaster loop, two forces combine to make the centripetal force required to keep the cart moving in a circular path - the cart's weight, and the reaction force of the track against the cart (except in the special case where the cart's weight alone is sufficient for...

Homework Statement A simple and very violent chemical reaction is H + H -> H_2 + 5 eV (1eV = 1.6x10^-19 J, a healthy amount of energy on the atomic scale). However, when hydrogen atoms collide in free space they simply bounce apart! The reason is that it is impossible to satisfy the laws of...

Disclaimer: I've never had a chemistry class in my life. I'm reading a journal article that states the following: S2O32- + 2O2 + H2O → 2SO42- + 2H+ has the standard Gibbs energy of −766 kJ/mol at 25ºC. So, this is energy produced per moles of what?! Reactant? Product? If so, which reactant or...

Homework Statement . question is as attached. answer is 2f/5..how do u get this? Homework Equations F=ma F= (5m)a a= F/(5m) The Attempt at a Solution gotten a=F/5m , but why the answer is 2f/5?

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...

The atmosphere consists of two toxic, and unfortunately abundant gases in our atmosphere. Carbon dioxide and methane. Carbon dioxide produced by factories are not needed in the atmosphere and cause harm. So is methane. Acegikmoqsuwy and I thought of an equation to solve this problem: CH4 + CO2...

Homework Statement 2AgNO3(aq) + CuCL2(aq) --> 2AgCl(s) + Cu(NO3)2(aq) The concentration of Ag(NO3)2(aq) at t = 30s is .42 mol/L. At t = 60.0 its concentration is .28 mol/L. What is the change in [CL^-] during this time? Homework Equations The Attempt at a Solution Not really sure even how...

1. Consider the reaction that happens when a photon collides with an atomic electron in rest ##\gamma+e^{-} <---> K^{-} + v_{e}##. The masses of all particles can be considered as known. What is the minimal energy that the photon needs to have to make this reaction work?2. Conservation of four...

Homework Statement A small block is shot into each of the four tracks as shown below. Each of the tracks rise to the same height. The speed with which the block enters the track is the same in all cases. At the highest point of the track, the normal Reaction is maximum in which track? 2...

Homework Statement Write equations to illustrate whether P4O10(s) is an Arrhenius acid or a base. Homework Equations P4O10(s) + H2O(l) will eventually have the H3O+ and a negative ion because it is a non-metallic oxide in water. The Attempt at a Solution I can think of at least 10...

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.

Homework Statement Two blocks with different masses are in contact on a frictionless surface. A force, Fp can be applied to either block. If the magnitude of Fp is the same on both cases, the force exerted by the heavier block on the lighter box is A) The same B) Greater when force Fp is...

Homework Statement is treated first with Li and then with CuI. The product reacts with chlorocyclopentane Homework EquationsThe Attempt at a Solution [/B] I don't know where to start exactly... it doesn't seem to be anything I've learned so far (substitution, addition ,elimination). All I...

Hi everybody, I have some troubles to define the enthalpy and entropy of a half reaction. If we consider the 2 following reactions : Anode : H2 = 2H+ + 2e- Cathode : 2H+ + 2e- + 1/2O2 = H2O So the global reaction is : H2 + 1/2O2 = H2O We know the global reaction's entropy can...

Homework Statement In one experiment, 22.9841 grams of 75.25% pure Pb(NO3)2 (pure Pb(NO3)2 has a molar mass of 331.2 grams) was mixed with 51.2354 grams of 81.21% pure CsI (pure CsI has a molar mass of 259.80992 grams): 2CsI(aq) + Pb(NO3)2(aq) → 2CsNO3(aq) + PbI2(s) After the reaction...

Hello, so I've been given this question and I get a different anwser then my friends. Can you check if what I wrote is right? If its wrong then can you tell me what have I done wrong? Sorry for the quality of the picture but my Paint skills are not so great :) I was measuring to the right...

Homework Statement The rate law for the reaction is found from experiment to be Suggest a mechanism consistent with the rate law. Homework EquationsThe Attempt at a Solution Here is the webpage with the solution http://www.umich.edu/~elements/07chap/frames.htm Here is the solution Rate...

Seasons' Greetings. I have been asked to express the reaction of H2N(CH2)3NH2 with HOOCCH2(C6H4)CH2COOH in a stoichiometric ratio. Would appreciate some guidance, not with the equation in particular, but the semantics of it.wirefree

Homework Statement Problem: I am told that the first mechanism is operative in saponification. The Attempt at a Solution However, this strikes me as wrong because the first mechanism involves the formation of dianion. Using hydroxide ion to abstract a proton and make that particular...

Homework Statement One mole of gas A, two moles of gas B, and one mole of inert gas I are fed into an adiabatic reactor of variable volume and constant pressure at 25 °C. At this temperature, the reaction yielding liquid R proceeds normally as: \textrm{A} (g) + \textrm{B} (g) \rightarrow...