The concept of starting concentration and equilibrium concentration

The starting concentration is the concentration of the reactants before the reaction starts.

The equilibrium concentration is the concentration of reactants and products when a chemical reaction reaches equilibrium.

The specific definition of analytical concentration is not precise and can be thought of as the total concentration of a substance added to a solution, but it can be abstracted by some examples.

For example, the analytical concentration of Na2CO3 is 1mol L

Then the analytical concentration of carbonate = the actual concentration of carbonate + the actual concentration of bicarbonate + the actual concentration of carbonic acid.

If the analytical concentration of the acid refers to the sum of the concentrations of unionized acid and ionized acid, and if chlorobenzoic acid is dimerized in the benzene phase, then its analytical concentration = 2 dimer concentration + unpolymerized chlorobenzoic acid.

In a mass balance, the analytical concentration of a component (i.e., the total concentration of the component added to the solution) is equal to the sum of the equilibrium concentrations of the components of each species, and the mathematical expression for concentration is the mass balance equation (MBE). For example, when the analytical concentration of the monobasic acid HA is c(ha), the mass balance formula is;

c(ha) total = [ha] + [a-]. Another example: in the salt solution NaCl solution, when the analytical concentration is C, then C= Na+ or = Cl-

Equilibrium

concentration) refers to the concentration of each type (species) present in the solution in the equilibrium state, with the symbol [.]

I show it, and some use it, too.

c (denotes.) For example, monobasic weak acid (Hx) exists in solution in two forms, H+ and X-, and the equilibrium concentrations of the two types are [H+] and [X-], respectively

The starting concentration of a reactant is the concentration of each reactant at the beginning of a reaction.

The equilibrium concentration refers to the concentration of each substance when the reversible reaction reaches equilibrium.

The starting concentration is the initial concentration of the substance in the container.

The equilibrium concentration is the concentration of the substance in the container when the reaction reaches equilibrium.

The differences between analytical and equilibrium concentrations are as follows.

1.The analytical concentration represents the sum of the equilibrium concentrations of each group of types (different forms of the same substance) after the solution system reaches equilibrium. It can be considered as the total concentration of a substance added to the solution or it can be understood by some examples.

If the analytical concentration of Na2CO3 is 1mol L, the carbonic acid will collapse the first radicle.

The analytical concentration = the actual concentration of carbonate + bicarbonate.

The actual concentration + the actual concentration of carbonic acid. For example, the analytical concentration of an acid refers to the sum of the concentrations of the unionized acid group and the ionized acid; For another example, chlorobenzoic acid is dimerized in the benzene phase, then its analytical concentration = 2 dimer.

Concentration + unpolymerized chlorobenzoic acid concentration.

The equilibrium concentration refers to the concentration of each type of body present in the solution in the equilibrium state of Pingqin, which is represented by the symbol [ ], and some are also represented by c( ).

1) Analyze the degree of concentrated jujube residue.

The amount of substance (acid or base) contained in a unit volume of solution, the concentration is the total concentration, referred to as the concentration.

2) Equilibrate the concentration.

In the equilibrium state, the concentration of the various types of Rongzhi in the solution is the same as above.

Example: In HAC solution: the equilibrium concentration is next to the Yanshu [HAC] and [AC-] analysis concentration C

hac]ac-]

BalanceThe formula for calculating the concentrationYes: aa(g) +bb(g)==certain conditions===ee(g) +dd(g) k = e] e * d] d a] a * b] b.

The equilibrium concentration refers to the concentration of each type (species) present in the solution when the equilibrium jujube is in the talking state, which is represented by the symbol [ ], and some are also represented by c( ). For example, monobasic weak acid (HX) exists in solution in the form of HX and X-, and the equilibrium concentrations of the two types are [HX] and [X-], respectively.

The analysis of energy consumption generated by the use of solid products in traditional thermodynamics.

A correction term was added to the equilibrium formula to calculate the equilibrium concentration of HCL gas in the dry purification process of stone bench ash absorbent, and the concept that the equilibrium concentration of reactive gas in the gas-solid reaction process increased with the increase of solid reaction rate was proposed for the first time. The results show that the equilibrium concentration of HCl decreases with the increase of temperature after the absorbent reaches a certain reaction rate.

The variation characteristics of the equilibrium concentration with the reaction rate and temperature can explain some experimental phenomena that cannot be explained by the traditional thermodynamic equilibrium formula, and the equilibrium concentration can be used to use the calcium-based absorbent dry to purify the purification efficiency and absorbent dosage of HCl in the exhaust smoke of the incineration grate. **The results can determine the scope of use, limitations and improvement directions of dry purification.

The above information refers to Encyclopedia - Equilibrium Concentration.

The effect of concentration on chemical equilibrium is:In the reaction carried out in solution, if the solution is diluted, the concentration of reactants and products decreases, and the rate of forward and reverse reactions decreases, but the degree of reduction is different, and the overall result is that the equilibrium moves in the direction of the large stoichiometric number in the equation.

Concentration is a noun in analytical chemistry. The meaning is the concentration expressed in the number of moles of solute contained in 1 liter of solution. The physical quantity of the solution composition is expressed by the amount of solute contained in a unit volume (molar number), which is called the molar concentration of the solute, also known as the quantitative concentration of the solute substance.

Commonly used concentration notations are:

Mass Percent Concentration (mass fraction, mm): Most commonly used. Refers to the mass of solute per 100 grams of solution, in grams.

Mass percentage = (solute mass (g)) solution mass (g)) 100% = solute mass (g)) solute mass (g) + solvent mass (g)) 100%.

Percent by volume (volume fraction, v v): Commonly used in alcohol. Refers to the volume of solute per 100 ml of solution, in milliliters.

Volume percentage concentration = (solute volume (ml) solution volume (ml)) 100% = solute volume (ml) (solute volume (ml) + solvent volume (ml)) 100%.

Parts per million (ppm): Refers to the mass of solute (in milligrams) per kilogram of solution.

Parts per million concentration = mass of solute (mg) mass of solution (kg).

Mass molar concentration: refers to the amount of solute (in moles) contained per kilogram of solvent.

Mass molar concentration = amount of solute substance (mol) Solvent mass (kg) 1m = 1 mol kg.

Molar fraction: the amount of solute material (mol) The amount of solution (mol).

Volumetric molar concentration (molar concentration): The amount of solute (in moles) per liter of solution.

Volume molar concentration = amount of solute (mol) volume of solution (l) 1m = 1mol l formula: c (concentration of the amount of the substance in the solution mol l) = n (the amount of the substance of the solute) v (solution ml).

Chemical equilibrium refers to the state in which the positive and reverse reaction rates of the chemical reaction are equal and the concentrations of the components of reactants and products no longer change in a reversible reaction under certain macroscopic conditions. It can be judged by δRGM= 0, A is the chemical potential of species A in the reaction. According to Le Chatre's principle, if a system that has reached equilibrium is changed, the system will change accordingly to counteract the change.

Chemical equilibrium is a type of dynamic equilibrium.

Generally, the change of the rate of forward reaction and the rate of reverse reaction in a reversible reaction indicates the process of establishing chemical equilibrium. The essence of chemical equilibrium: the rate of positive reaction is equal to the rate of reverse reaction.

It is a term in analytical chemistry. The meaning is the concentration expressed in the number of moles of solute contained in 1 liter of solution. The physical quantity of the solution composition is expressed by the amount of solute contained in a unit volume (molar number), which is called the molar concentration of the solute, also known as the quantitative concentration of the solute substance.

The formula for calculating the equilibrium concentration constant is: aa(g)+bb(g)==certain conditions===ee(g)+dd(g)k=[e] e*[d] d [a] a*[b] b.

The equilibrium concentration refers to the concentration of each type (species) present in the solution in the equilibrium state, which is represented by a symbol, and some are also represented by c(). The monobasic weak acid (Hx) exists in the solution in two forms, Hx and X-, and the equilibrium concentrations of the two types are [Hx] and [X-], respectivelyThe equilibrium concentration is generally in square brackets.

Indicates that the equilibrium concentration of pure liquid can be considered as making rubber 1.

Taking HAC as an example, if the total concentration of pure hunger is C, HAC exists in two forms of HAC and AC- in aqueous solution, so its equilibrium concentration is expressed as: C=[HAC]+[AC-] or C=C(HAC)+C(Ac-).

c=kc*[a]a*[b]b。The equilibrium concentration refers to the concentration of a substance in the solution when it reaches the equilibrium state, c is the equilibrium concentration, kc is the equilibrium constant, [a] and [b] represent the concentrations of reactants a and b respectively, and a and b represent the coefficients of reactants a and b in the chemical equation respectively.

The effect of concentration on chemical equilibrium, as follows:

1. When the concentration of reactants increases, the chemical reaction rate accelerates, and the equilibrium proceeds in the direction of positive reaction.

2. When the concentration of reactants is small, when the solution is diluted in the opposite direction of the reaction, the ionization slip process is regarded as a chemical reaction. It can be seen that the concentration of ions decreases, that is, the concentration of the product decreases, and the reaction proceeds in the direction of the positive reaction, and it is also destroyed and constantly moves in the direction of ionization.

3. If you change a condition that affects the equilibrium, such as concentration, pressure, or temperature, the equilibrium will move in a direction that can weaken the change. This is Le Chatley's principle, which is applicable to various principles of chemical equilibrium.