Questions about conversion rates in reversible reactions confused .

Based on the reaction you give, the equilibrium is not moving in a positive direction.

The example you gave is a gas-phase reaction, in the case of constant temperature and constant volume, increasing the concentration of gas-phase reactants is equivalent to adding reactant gas, and also equivalent to increasing the pressure of the system, at this time, the balance of the reaction will move to the side with a small volume, that is, the direction of the reactants, so although the reaction will indeed be dominated by the positive reaction after adding reactants, the equilibrium will be reversed, and the conversion rate will be reduced.

The effect of the "reactant concentration" on the equilibrium of the gas phase reaction is meaningless, because P and V are mutually influencing, and only in the liquid phase environment P and V are relatively unaffected, it is meaningful.

By the way, I think you have a problem with your understanding of the concept of "balanced movement". Equilibrium movement is a measure of which of the two ends of a reaction is more or less when it reaches chemical equilibrium, rather than a question of which is more or less at a certain point in which direction is forward or opposite – to put it simply, it is a problem of chemical thermodynamics, not chemical kinetics.

Conversion rate = amount of substance converted (or mass or concentration) Total amount of substance (or mass or concentration).

For example, at the beginning, it was 1mol L of PCL5, and the concentration of it was increased to 2mol L of PCL5, which is 2mol L of PCL5, but although this is to make the reaction to the positive reaction, this reaction is reversible, and it must be less than twice the beginning of the transformation, at this time you think about it, the denominator becomes twice the beginning, but the numerator is less than twice the beginning, and the result is definitely less than the beginning value, that is, the conversion rate is reduced. If you figured it out, remember!

Because the reactants increase dramatically, and the amplitude of the equilibrium movement is smaller, the conversion rate decreases.

I think it's because the total amount has increased.

For substances that can undergo a chemical imitation reed reaction:

1. Increase the concentration of reactants, that is, increase the pressure of the state substance, and accelerate the chemical reaction rate; Stuffy.

2. The temperature increases, and the chemical reaction rate accelerates;

3. For solid substances, increase the surface area of reactants, and accelerate the chemical reaction rate;

4. Use positive catalyst to reduce the activation energy and accelerate the chemical reaction rate.

Reactant conversion rate of a reversible reaction: the percentage or fraction of the conversion of a reactant, the conversion rate is for the reactant. If there are multiple reactants, the conversion rates calculated from different reactants may be different, but they all reflect the same objective facts.

Therefore, the conversion rate can be calculated based on the reactants.

Most of the reactions are reversible, some reactions are not reversible under general conditions, and changing the conditions (such as placing reactants in a closed environment, high-temperature reactions, etc.) will become reversible. For reversible reactions, under certain conditions, whether starting from a positive reaction or a reverse reaction, the same equilibrium state can be established, i.e., the same equilibrium state can be reached with different starting conditions.

Summary. Hello dear dear to you, I am glad to answer the <> that irreversible reaction conversion rate is related to reaction conditions, equipment, etc., or related to balanced movement

Hello dear dear to you, I am glad to answer the <> that irreversible reaction conversion rate is related to reaction conditions, equipment, etc., or related to balanced movement

Chemistry is a basic natural science that studies the composition, structure, properties, transformation and application of matter at the atomic and molecular levels. It originates from life and production practices, and continues to evolve with the progress of human society. Different from particle physics and nuclear physics, which study the smaller scale, the material structure of atoms, molecules, ions (groups), chemical bonds, intermolecular forces and other interactions are studied in chemistry, and the scale in which they are located is the closest to the macroscopic in the microscopic world, so their natural laws are also most closely related to the physical and chemical properties of matter and materials in the macrocosm of human existence.

As an important bridge between the microscopic and macroscopic material worlds, chemistry is one of the main methods and means for human beings to understand and transform the material world. <>

There should be no equilibrium movement in the irreversible reaction, so why can it be related to equilibrium movement?

Theoretically, all chemical reactions can be regarded as reversible reactions, but those with large equilibrium constants can be regarded as irreversible, so there is a state of chemical equilibrium. <>

Summary. The answer is: for a reversible reaction, a reaction gas is added, and if two substances are involved in the reaction, the conversion rate of one substance added decreases, while the other increases.

The conversion rate of an unequilibrated reaction in a reversible reaction.

The answer is: for a reversible reaction, a reaction gas is added, and if two substances are involved in the reaction, the conversion rate of one substance added decreases, while the other increases.

What I mean by this is, what is the expression for the conversion rate when it is not equilibrium, is it the conversion rate after the combination of the forward and reverse reactions per unit time, or the conversion rate of the positive reaction per unit time.

The answer is: conversion rate = conversion amount The initial amount is such as a + B = c, add a balance to the right, and the conversion rate of b becomes larger. But the equilibrium is weak, and the denominator of the A conversion rate increases more, so it decreases. It is the conversion rate of the positive reaction per unit of time.

If the catalyst is suddenly deactivated as the temperature rises under the action of the catalyst, will the conversion rate per unit time suddenly decrease?

The answer is: the conversion rate per unit of time also drops suddenly.

The amount of the total substance.

Change depends on the conditions on the question.

Take it as an example: 1. The volume of the closed container is fixed, and inert gas is added.

Although the pressure of the system increases, the equilibrium does not move, because the inert gas does not participate in the reaction, and the concentration of each component of the equilibrium gas mixture does not change in any way due to the fixed volume, so the equilibrium does not move.

2. The volume of the closed container is variable, that is, when the closed container is filled with inert gas under constant pressure, it moves in balance. Because when the volume increases due to the constant pressure after being filled with inert gas, the concentration of each component of the equilibrium gas mixture decreases accordingly, which is equivalent to reducing the pressure, and the equilibrium moves in the reaction direction of the increase in the volume of the gas.

1) Concentration: When other conditions remain unchanged, increase the concentration of reactants and the rate of chemical reaction.

Quicken; The opposite is slow.

Note: The concentration of solids and pure liquids can be considered constants. Since the reaction between solid substances is only related to the contact area, the change in the amount of solid matter has no effect on the reaction rate.

2) Pressure: When other conditions remain unchanged, increase the pressure of the gas reaction system and accelerate the chemical reaction rate; The opposite is slow.

Note: Changing the pressure, the root cause of the effect on the rate of chemical reaction is the change in concentration. Therefore, when discussing the effect of pressure on the reaction rate, it is necessary to distinguish the causes of pressure changes.

For gas reaction systems, there are the following cases:

At constant temperature: increase the pressure, shrink the volume, increase the concentration, and accelerate the reaction rate.

Constant capacity: aThe concentration of the gas-filled reactants increased, the total pressure increased, and the reaction rate accelerated.

b.The total pressure of the "inert gas" increases, but the concentration of each substance remains unchanged and the reaction rate remains the same.

At constant pressure: Fill with "inert gas" The volume increases, the concentration of each reactant decreases, and the reaction rate slows down.

3) Temperature: When other conditions remain unchanged, the temperature is increased and the reaction rate is accelerated.

For every 10 times the temperature increases, the chemical reaction rate increases to 2-4 times. Increasing the temperature of the reaction system is an effective way to increase the reaction rate.

Catalyst: The use of positive catalysts can speed up the rate of chemical reactions. Otherwise, if not specified, it refers to the catalyst.

Anything that can affect the equilibrium may change the chemical conversion rate. For example: 1: Temperature: will definitely change the chemical conversion rate.

2: Pressure: may change the chemical conversion rate (peer reaction and non-gas phase reaction cannot change the chemical conversion rate).

3: The concentration of reactants and products can change the chemical conversion rate.

4: Other factors, such as: ultraviolet rays, microwave and other conditions.

The above factors make the chemical conversion rate larger? Getting smaller? To be specific.

Summary. The problem belongs to the "one-sided principle", according to the principle of constant equilibrium coefficient at a certain temperature, for the forward and negative processes of the same reaction, the equilibrium coefficient is reciprocal to each other, and when the final stable state is reached, the concentration of each component in the forward and reverse reaction is equal, to give you an example, a = b + c is a positive reaction, under the same external conditions, the conversion rate of a is a certain (positive reaction conversion rate, if a is all reacted, a certain amount of b and c (proportional to a.) will be generated. On the other hand, for the reverse reaction, since the final state of the reaction, the concentration of each component (the same substance in the positive and reverse reactions) does not change, so in the previous hypothesis, when B and C of the reverse reaction are converted into the corresponding proportion of A, the total amount of reactants generated by the reverse reaction A and the positive reaction is equal to the amount of A originally added, so the sum of the conversion rates according to the proportion is 100%.

The problem belongs to the "one-sided principle", according to the principle of constant equilibrium coefficient at a certain temperature, for the forward and reverse processes of the same reaction, the equilibrium coefficient is reciprocal to each other, and when the final stable state is reached, the concentration of each component in the forward and reverse reaction is equal, to give you an example, A=B+C is a positive reaction, and under the same external conditions, the conversion rate of A is certain (positive reaction conversion rate, if A is all reacted, the hail burial will generate a certain amount of B and C (proportional to A. On the other hand, for the reverse reaction, since the final state of the reaction, the concentration of each component (the same substance in the positive reaction and the reverse reaction) does not change, so in the previous hypothesis, when B and C of the reverse reaction reaction are converted into the corresponding proportion of A of the source worm, the total amount of reactants consumed by the reverse reaction A and the positive reaction is equal to the amount of reactants originally added to A, so the sum of the conversion rates obtained by Xingling according to the proportion is 100%.

Can you add, I don't quite understand it.

It's an equal proportional conversion. Because the amount you put in is constant, it does not change according to the concentration of each component.

Increases the concentration of a reactant due to chemical equilibrium.

Moving in the direction of the positive reaction can improve the conversion rate of other reactants.

However, the conversion rate of this reactant is reduced.

Since a change in temperature must shift the chemical equilibrium, changing the temperature will change the conversion rate of the reactants.

Changing the pressure, if the chemical equilibrium shifts, changes the conversion rate of the reactants; If the chemical equilibrium does not move (a reaction in which the volume of the gaseous substance does not change before and after the reaction), the conversion rate of the reactants cannot be changed.

Positive reaction endothermy: increase the temperature and increase the conversion rate. Lower the temperature and lower the conversion rate. Positive reaction volume reduction: increase the pressure to improve the conversion rate, reduce the pressure to reduce the conversion rate. Increase the concentration of one reactant and increase the conversion of another.