Whether the equivalent equilibrium applies to reactions with the participation of solids

Know > Education Science What to do if there are solids in the chemical equivalence equilibrium Report violations, report infringement complaints|2010-10-30 17:05 Questioner's reward: 50 points |Last night's stars, tomorrow's maple |From the phone to know |Classification:

Education Science |Viewed 835 times.

I'm going crazy, and now I see two factions, one says it doesn't have an impact, it's okay, and the other says it needs to be considered. For example: constant temperature and constant capacity, 2A+B can be reversible 3C+D (solid state), if 2mola and 1molb are originally added, when the equilibrium is reached, the volume fraction of C is A, how to feed the material is A, if I only put 3molC and not D, can I do it?

Or if I vote 3molc and is it only the and reaction? What about an excess of 3molc? I don't understand!

When discussing the effect of chemical pressure on chemical equilibrium, the solid can be disregarded, because the volume occupied by the solid is relatively small compared to the gas, so it is negligible and the pressure has no effect on the change of the liquid, so the solid D can not be discussed at this time.

However, when the amount of other substances is changed, the chemical equilibrium will be changed, and if the equilibrium moves in the direction of the positive reaction, the mass of substance d will increase when the reaction is equilibrium; If the equilibrium moves in the direction of the opposite reaction, then when the reaction is equilibrium, the mass of substance d decreases.

Only gases, solids and liquids will not do.

Equivalence balance.

It refers to the reversible reaction under certain conditions, the starting amount is different, but the mass fraction (or volume fraction) of any of the same components is equal when the equilibrium is reached, so that the equilibrium established separately is called equivalent equilibrium.

Equivalent equilibrium under different conditions.

1.For general reversible reactions, an equilibrium is established under constant temperature and constant capacitance, and the amount of substances added at the beginning is changed, and if the amount of substances that can be converted into the same half of the substances according to stoichiometry is the same as the original equilibrium, the two equilibrium are equivalent.

Equivalence. is a special equivalence balance. If the two reactions reach equilibrium, the volume fraction of each substance, the quantity concentration of the substance, and the amount of the substance correspond to the same, this equilibrium is equivalent equilibrium. Such as a reaction that is done at the same time at isothermal isobaric pressure (or at the same time at isothermal isovolumetric level).

2so2+o2

2SO3 A 2mol

1mol0B.

Obviously, 1mol is done at the same time at isothermal isobaric (or at the same time isothermal isovolumetric).

The reaction of H moli2 is also equivalent to that of 2molhi. In short, as long as the amount of substances on the same side of the same side is the same as the original reaction according to the stoichiometric ratio of the reversible reaction, the equilibrium that they achieve at the same time at isothermal isobaric pressure (or at the same time at isothermal isovolumetric) is equivalent equilibrium.

Similar balance. We know that there is a certain relationship between the three quantities of reactants and products (initial quantity, change amount and flat measurement) after a reversible reaction reaches equilibrium.

1) The amount of change between reactants and products is always a relationship between the ratio of stoichiometric numbers.

2) If the initial quantity of reactants is the ratio of stoichiometric numbers, then their change and measurement are all stoichiometric ratios; If the initial amount of reactants is not a ratio of stoichiometric numbers, then their equilibrium is not a ratio of stoichiometric numbers. (Same for spawns).

When there are several different initial quantities of reactants and products after a reversible reaction reaches the equilibrium state, there are the same equilibrium laws and relationships mentioned above when they conform to the standard state.

If the initial amount of reactants is not a multiple of the stoichiometric relationship, the following relationship exists:

1) The amount of change in reactants and products is always a stoichiometric relationship.

2) If the two groups of initial quantities of reactants are multiples, then the corresponding changes and equilibrium are also multiples. If the two sets of initial quantities of reactants are not multiple, the corresponding equilibrium quantities will not be multiples. (Same for spawns).

If the given reaction is a reaction in which the total volume of gaseous matter remains unchanged before and after the reaction, an increase or decrease in pressure cannot cause the chemical equilibrium to move; The amount of reactants or products is increased exponentially, and the equilibrium state does not change.

There is a certain correspondence between some of the equilibrium quantities involved in the above two cases. Let's call it the balance of similarities. They may be in the same equilibrium state, but some quantities have a multiplier relationship.

If two chemical equilibrium states are similar, they should conform to the principle of similarity equilibrium (abbreviated as the similarity principle).

Relative equilibrium means that when equilibrium, the fraction and conversion rate of the components are equal, but the components, that is, the amount of the substance, are not equal. Whereas, absolute equilibrium is when the amount of matter, conversion rate, etc., is completely equal at the time of equilibrium.

Differentiation method: If the values are exactly equal when the material is converted to one side, it is an absolute equilibrium. If it is proportional, it is relatively balanced.

Equivalence equilibrium is actually a method of doing problems.

There are three main categories to master in high school.

1.Constant temperature and constant volume equal volume reaction (equivalent reaction): refers to the fact that for this type of reaction, as long as the reactants do not change, the conversion rate and equilibrium constant do not change.

That is, n does not change, c does not change, and fai does not change (the quantity fraction of matter).

2.Constant temperature and pressure reaction: only n is required to form a multiple relationship to achieve the equivalent equilibrium, so c does not change, and fai does not change.

3.Constant temperature and constant volume equal volume reaction: N is a multiple relationship, that is, the equivalent equilibrium is reached, at this time, C is a multiple relationship, and FAI is still unchanged.

The sign of equilibrium is that the quantity fraction of matter does not change.

The best way to see if it is an equivalent equilibrium is to reflect the product reactants to the positive side of the reaction, and see if their relationship is equal or multiple, or neither.

These two are quite different.

Chemoballast equilibrium refers to the rate at which a positive reaction occurs in a reversible reaction.

When the rate of the reverse reaction is equal, the reaction reaches dynamic equilibrium, which is called chemical equilibrium.

Equivalence balance. Yes, under certain conditions (isothermal isochorric or isothermal isobaric), the mass fraction of any of the same components is given after equilibrium has been reached by the same reversible reaction with a different initial addition situation.

or volume fractions), such equilibrium is the equilibrium of Zhenghui.

The establishment of the same equilibrium or similar equilibrium is related to external conditions, one is constant temperature and constant capacity, and the other is constant temperature and constant pressure. To put it simply, an action (generally divided into coefficients with the same or different coefficients) under specific conditions achieves a consistent equilibrium state.

If you talk about the question type.

Chemical equilibrium is mostly a matter of changing conditions to ask for trends or graphs, or to find equations for rates.

A class of kinds. Equilibrium is given to the equation and then the conditions are changed to ask the result, or vice versa.

Quite simply, the essence of the equivalent equilibrium is that the two equilibrium are exactly the same, and the essence of the analogous equilibrium is that the reactants added to the equilibrium of the two spines are simply proportional and cannot reach a completely flump-like state.

If equilibrium is established from the direction of the reverse reaction, the condition that the amount of the starting species of d should be met is d.

If mol a and mol b are added, the amount of the starting material for c and d should meet the requirements of c = and d respectively

d is a solid, as long as the quantity satisfies the lowest measurement relationship, more has no effect on the equilibrium. A, B, and C are required to satisfy the reference state in the equivalent equilibrium.

Reference conditions: initial 2 mol a and 1 mol b, c and d are 0 equilibrium state: a:

b： c： d：

In fact, as long as 0 is sufficient) Reverse equilibrium, the generation of a and b requires c for, d is, plus c at equilibrium, so c is needed, and d is solid because it is solid, so as long as it is greater than.

c=,d add mol a, mol b, and to reach equilibrium, and so it needs to react with and, plus c at equilibrium, so c needs to be, and d is solid because it is solid, so as long as it is greater than.

c=，d≥

It refers to the mass fraction of any of the same components in a reversible reaction under certain conditions, when the starting amount is different, but the equilibrium is reached.

or volume fractions), so that the equilibrium established separately is called equivalent equilibrium.

Equivalent equilibrium under different conditions.

For general reversible reactions, equilibrium is established under constant temperature and constant capacitance conditions, changing the amount of substance added at the beginning.

If the amount of the substance that can be converted into the same half of the substance according to the chemical spike sedan measurement is the same as the original equilibrium, then the two equilibrium are equivalent.

At a constant temperature and pressure, change the amount of substance added at the beginning, as long as the chemical equation is followed.

The ratio of coefficients is the same as that of the original equilibrium, and the two equilibrium are equivalent.

At constant temperature and constant volume, for the reversible reaction of the paraspike with the number of gas molecules unchanged before and after the reaction, as long as the proportion of the amount of reactants (or products) is the same as that of the original equilibrium, the two equilibrium is equivalent equilibrium. (Equivalent to the equivalent equilibrium at constant temperature and pressure, because the equilibrium is not affected by pressure).

The starting amount is different, but the mass fraction (or volume fraction) of any one of the same components is equal when the equilibrium is reached, and the equilibrium established separately is called equivalent equilibrium.

For general reversible reactions, the equilibrium is established under constant temperature and constant capacitance, and the amount of substances added at the beginning is changed, and if the amount of substances that can be converted into the same half of the substances according to the stoichiometric collapse number is the same as the original equilibrium, the two equilibrium are equivalent.

Under constant temperature and pressure, the amount of substances added at the beginning of the change is the same as the original equilibrium when the amount of substances converted into the same half of the matter is the same as the original equilibrium according to the ratio of the coefficient ratio of the chemical equation.

At constant temperature and constant volume, for a reversible reaction with the same number of gas molecules before and after the reaction, as long as the proportion of the amount of reactants (or products) is the same as that of the original equilibrium, the two equilibrium is equivalent equilibrium. (It is equivalent to the equivalent equilibrium at constant temperature and constant pressure in the ruler circle, because the equilibrium is not affected by pressure).

Equilibrium refers to two reversible reactions, and the amount of reactant species is the same and the amount of the product is the same after the equilibrium of these two reversible reactions.

Equivalent equilibrium refers to two reversible reactions, and after the equilibrium of these two reversible reactions, the number of integrals of the reactant is the same, and the volume fraction of the product is the same.

The following refers to pure gas reactions).

1.When the sum of the stoichiometric numbers on both sides of the reaction is unequal, if the amount of the substance that is fed twice (there may be reactants and products) is converted to the same side (reactant or product) according to the measurement number of the reaction equation, the amount of the substance is exactly the same, then it is equivalent to equilibrium.

2.When the sum of the stoichiometric numbers on both sides of the reaction is equal, if the amount of the substance that is fed twice (there may be reactants and products) is converted to the same side (reactant or product) according to the measurement number of the reaction equation, the ratio of the amount of the substance between the reactants is equal to the first time, and the equilibrium is equivalent.

3.At constant pressure, regardless of whether the sum of the stoichiometric numbers on both sides of the reaction is equal or not, it is the same as 2.