Water Ionization Equilibrium Constant, what is the ionization equilibrium constant of water?

Water is an extremely weak electrolyte that is partially ionized as "H+" and "Oh-".

And there is an ionization equilibrium as follows:

H2O (liquid) H+ +OH-

According to the law of mass action, the ionization equilibrium of water can be expressed as:

h+][oh-]/[h2o]=k

At 25, one liter of water is equivalent to moles of water, and the concentration of [H+] and [oh-] ions in the water is molar liters each.

[H2O] in the above equation is the concentration of undissociated water molecules, which should be equal to.

It's too small compared to that.

, it can be ignored so that [h2o] is equal to moles, i.e. one.

Constant. This makes it possible to merge it with the ionization constant k into a new constant:

h+][oh-]=k[h2o]=k[ or.

h+][oh-]=kw

Substituting molar liters into [h+] and [oh-] yields:

h+][oh-]=(

For the sake of simplicity, at room temperature, we often use kw=1*10 -14. (Symbol.)

Moles liters are generally not written, they are omitted).

Ionization equilibrium constant: The equilibrium constant of ionization equilibrium.

The ionization equilibrium constant of water is: k==The ionization constant is the equilibrium constant of ionization equilibrium and describes the ionization capacity of a weak electrolyte at a certain temperature.

When weak electrolytes with polar covalent bonds (e.g., some weak acids, weak bases) are dissolved in water, their molecules can weakly ionize ions; At the same time, the corresponding ions in the solution can also be combined into molecules. In general, since the beginning of the above reaction, the rate at which the ions of the weak electrolyte molecules are ionized decreases, while the rate at which the ions recombine into the weak electrolyte molecules increases, and when the reaction rates of the two are equal, the solution reaches ionization equilibrium. At this time, the concentration of electrolyte molecules and ions in the solution are in a stable state and do not change, respectively.

A change in the direction of equilibrium.

The ionization of weak electrolyte molecules and the combination of ions into molecules, together form a set of reversible reactions. The reaction direction of ionization of weak electrolyte molecules is often the positive reaction direction, and the reaction direction of ions recombined into weak electrolyte molecules is the reverse reaction direction.

Like chemical equilibrium, ionization equilibrium can be moved due to changes in conditions such as concentration, temperature, acidity and alkalinity, etc.

WateryIonization equilibrium constantkw about 10 -14.

The ionization equilibrium constant of water is hydrogen ions and hydroxides.

are all 1*10 -7, and the concentration of water is calculated in the same way as the concentration of other substances, assuming that there is 1l of water, that is, 1000 grams of water, the molecular weight of water is 18, so 1000 grams is 1000 18=, so the concentration of water is.

So the ionization equilibrium constant of water is (1*10 -7)*(1*10 -7). In organic chemistry, pka= for water, this is how it is calculated.

Relation to the ionization equilibrium constant and temperature of water:

The ionization equilibrium constant of water is a pure liquid, and [H2O] can be seen as a constant, so KW=[H][OH-]. The kw value is temperature dependent, at 25, kw = [h] [oh-] = 1 10-7 = 1 10 7 = 1 10-14. For the sake of computational simplicity, this value is often used as the ion product of water at room temperature.

In a dilute aqueous solution of a substance, [H2O] and pure water are almost identical to [H2O], so KW is also almost equal.

In any acidic (e.g., changxin or alkaline) solution, both h and oh- are present, except that the relative magnitude of [h] and [oh-] is different. At room temperature, the product of [h] and [oh-] is equal to 1 10-14. Hence the acidity and alkalinity of the aqueous solution.

As long as it is expressed in terms of the concentration of one ion (H or OH-).

The ionization equilibrium constant of water refers to the chemical equilibrium constant at which the equilibrium reaction of self-dissociation occurs at a certain temperature in water, which is usually expressed as kw.

Under standard conditions (25°C), the value of the ionization equilibrium constant kw of water is about 10 (-14).

The reaction equation is: H2O H+ +OH-

kw = h+][oh-]

In pure spring water, the concentration of [H+] and [oh-] is equal because the water is neutral. Thus, under standard conditions, the concentration of [H+] and [OH-] is 10 (-7) mol liters.

kw = × 10^(-7))(10^(-7)) 10^(-14)

The value of the ionization equilibrium constant kw of water changes with temperature. The value of kW will also be different at different macro temperatures.

The ionization equilibrium constant of water is: kc = [h+] [oh-] h2o].

The ionization constant is calculated by k(ionization) = c[a+] x·c[b-] y c[axby], where c[a+], c[b-], and c[ab] represent the concentration of a+, b-, and axby at ionization equilibrium, respectively.

The factor influencing the ionization equilibrium constant is temperature, for endothermic reactions, the higher the temperature, the greater k and the opposite for exothermic reactions. Only the temperature change changes, and the value does not change when the pressure change leads to the equilibrium movement.

Applications of the ionization equilibrium constant.

The ionization equilibrium constant represents the relative strength of the weak acid, and the salt generated by the weak acid will be hydrolyzed.

In short, the topic involving the ionization equilibrium constant must first judge the relative strength of the acid according to the ionization constant, arrange the relative strength of the acid from strong to weak, and then proceed according to the requirements of the topic.

The above content refers to Encyclopedia - Ionization Equilibrium Constant.

Encyclopedia - Water.

The ionization equilibrium constant of water is: k==

Water is an extremely weak electrolyte that is partially ionized as "H+" and "Oh-".

And there is the following ionization equilibrium: H2O (liquid) H+ +OH- According to the law of mass action, the ionization equilibrium of water can be expressed as: H+] K At 25, one liter of water is equivalent to moles of water, and the concentration of H+] and Oh-] ions in the water is molar liters each.

Law of Ionization Equilibrium Constant of Water:

The magnitude of the ionization equilibrium constant reflects the degree of ionization of the weak electrolyte, which varies at different temperatures.

At the same temperature, the ionization equilibrium constant of the same electrolyte is the same, but the conversion rate increases as the concentration of the weak electrolyte decreases. From the arithmetic square root of the degree of dissociation at this temperature a=(k starting concentration), it can be seen that the lower the concentration of weak electrolytes, the greater the degree of ionization.

The above content refers to Encyclopedia - Ionization Equilibrium Constant.

Ionization constant. is the equilibrium constant of ionization equilibrium, which describes the weak electrolyte at a certain temperature.

ionization capacity.

When the ionization of a weak electrolyte reaches equilibrium under certain conditions, the concentration of various ions generated by ionization in the (aqueous) solution is based on the chemical equation.

the ratio of the product of the power of the quantity in and the product of the concentration of the unionized molecule in the solution to the power of the number of the measurement in the chemical equation;

That is, the ratio of the product of the concentration of each ion ionized in the solution (c(a+)*c(b-)) to the concentration of the unionized electrolyte molecule in the solution (c(ab)) is a constant, which is called the ionization equilibrium constant of the weak electrolyte.

This constant is called the ionization equilibrium constant, or ionization constant for short.

It should be noted that the ionization equilibrium constant is only applicable to the calculation of weak electrolytes, strong electrolytes.

Not applicable*. <

The ionization equilibrium constant of water is usually expressed in kw, which is the constant of the product of the concentrations of hydrogen ions (h+) and hydroxide ions (oh-) produced by the automatic ionization of water at a certain temperature. Under standard conditions, the ionization equilibrium constant kw value of water is 10 (-14).

(2) Application of knowledge points:The value of the ionization equilibrium constant kw of water has a wide range of applications in the field of chemistry and physics. It is used to calculate the concentration of hydrogen ions and hydroxide ionic ions in water-soluble bridges, to understand acid-base properties, and to calculate pH and acid-base neutralization reaction equations.

(3) Explanation of knowledge point examples:Here is an example question about the ionization equilibrium constant kw of water:

Question: What is the ionization equilibrium constant of Sixiao water?

Answer: The ionization equilibrium constant kw of water is 10 (-14). This value represents a product of 10 (-14) of the concentrations of hydrogen and hydroxide ions in water under standard conditions.

This means that in pure water, the product of the concentration of hydrogen ions and the concentration of hydroxide ions is constant at this value.