# Questions tagged [reaction-coordinate]

Questions related to abstract one-dimensional coordinates which represent progress along a reaction pathway.

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### Gibbs free energy versus reaction progress plots

I am trying to make sense of these two graphs. They appear to have similar axes, yet display different curves. Please let me know if this understanding is correct: In the top image (x-axis = "...
• 11
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### Energy values of steam reformation, water gas shift, hydrogen and methane burning seem to not add up correctly [closed]

I found the following reactions including the Energy-Delta all in Wikipedia and in at least one more source each: (Delta with "-" are exothermic reaction which is generating heat) Steam ...
• 139
864 views

### Impact of temperature on an Energy profile diagram

What happens to the energy profile diagram if you increase the temperature of the system? From my understanding, I think the whole diagram would shift upwards, as the reactants and products will both ...
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### How change in potential energy corresponds to change in enthalpy?

So while reading about activation energy , I came across this graph : Here, change in potential energy of reactant and product is depicted as ${ΔH}$, but at constant pressure and temperature , ...
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1 vote
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### Organic-catalysis microwaves [closed]

When we perform a organic reaction without any addtional catalyst except that the reaction is carried out under microwave condition we can accelerate this reaction in comparison with one under heating ...
1 vote
2k views

### How to draw a reaction coordinate diagram for SN1 mechanism?

How would you draw a reaction coordinate diagram for an SN1 mechanism with the following conditions? each step in the mechanism (there are 2 steps) is favorable the second step of the mechanism is ...
155 views

### Potential energy surface in transition state theory

I would like to study the typical reaction from the transition state theory: $$\ce{AB + C <=> ABC^‡ -> A + BC}$$ Assuming $\ce{ABC^‡}$ is a colinear molecule, the potential energy surface of ...
• 309
1 vote
852 views

### Why is the top SN2 reaction faster? (Molecular Orbital Theory)

I'm having trouble understanding why the top SN2 reaction proceeds faster. I know that benzylic and allylic halides react faster in SN2 reactions than non-conjugated halides. I think it's because the ...
1 vote
91 views

### Endothermic or Exothermic [closed]

Is an endothermic reaction always endothermic at all conditions of pressure, temperature etc.? Similarly for exothermic... I mean is sign of ∆H always the same as sign of ∆H°? This might seem to be a ...
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564 views

### Hessian Matrix and Physical directions: Potential Energy Surface

How do the eigenvectors of the Hessian Matrix for potential energy surface correspond directly to the physical directions of translation, rotation and vibration? I see that they might correspond to ...
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649 views

### Relationship between Gibbs free energy and potential energy (related to reaction coordinate diagrams)

For a rate law, the rate constant $k$ is given by the equation $$\ln k = \ln A - \frac{E_\mathrm{a}}{RT}\tag{1}$$ If $k_\mathrm{fwd}$ is the forward rate constant and $k_\mathrm{rev}$ is the reverse ...
1k views

### Y-axis of the reaction co-ordinate graph

In the graph of the reaction co-ordinate, is the $y$-axis that is used $∆H,$ $∆U$ or $∆G$?
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### AP Chem Question about Reaction Rate - Confused?

I found this question in the AP Chem book, and I understand why B is the answer (as the answer key says). However, I don't understand why D is not also correct. The question is: A multistep reaction ...
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1k views

### Probability of the single molecule reaction to happen

I am trying to simulate the single particle second order reactions with known rate constants $k_1$ and $k_{-1}$ in Python. The point of this simulation is to fit the real experimental data to the ...
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1 vote
115 views

### Is it possible to define the coordinates of an atom using other coordinates while optimizing in gaussian 16?

I know it is possible to fix the value of composite expressions using generalized internal coordinates (gic) in gaussian 16. But is it possible to assign that value to the coordinate of another atom. ...
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### Finding direction of the reaction using Affinity of the reaction

I encountered following reaction: $$\ce{CO + 1/2 O2 -> CO2}$$ I am provided with the composition of the various gases at $\pu{1000K}$ and am asked the direction of the reaction by finding the ...
• 129
1k views

### Auto-catalysis Mechanism

I just read about the theory of auto-catalysis, and here's one thing which is sort of unclear to me: In this type of catalysis, one of the reaction product catalyses the reaction. For example, in ...
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741 views

### Is there any empirical upper limit for order of reaction?

I learned from one of my teachers that empirically reaction with order greater that 3 are never found. But, I am suspicious of the truth value of his claim. To add to my suspicion there is this paper ...
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### Why is law of mass action only applicable for elementary reaction?

Why can't we apply law of mass action for non-elementary reaction? Why does is vary with the rate law in case of non-elementary reactions?
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7k views

### Law of Mass action VS Rate law [duplicate]

The Law of mass action has 2 parts - the equilibrium rate part & the reaction rate part. The "reaction rate part" states that rate of a reaction is directly proportional to the product of active ...
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1 vote
62 views

### How to determine which normal mode leads to the transition state (numerically)? [closed]

I would like to get the normal mode of vibration which leads to the transition state. Do you know any software for this problem? If no, could you offer an algorithm to generate it? By the way, is ...
• 339
81 views

### Find reaction heat of a reaction [closed]

1) A(s)+O2(g) →Ao2; ΔH^0=-394kj/mol 2)AO(g)+ $\frac{1}{2}$O2(g) →AO2; ΔH^0=-283kj/mol 3)A(s)+ $\frac{1}{2}$O2(g) →AO(g); ΔH^0=-Xkj/mol Find the value of X? I want to know How to find this value.
105 views

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### What does "reaction coordinate" mean? What does it mean when a reaction has TWO reaction coordinates?

I'm familiar with the concept of a reaction coordinate from high school chemistry as some generic conformational parameter that all of the intermediate states of a chemical reaction lie upon. Recently,...
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