means that the electrolytic solution of the solute is completely dissolved in a solvent or a solution partially dissociated ions. Solute is the electrolyte. Having a conductive characteristic of the electrolyte solution, acid, alkali, salt solution are electrolyte solution. The electrolyte solution is an electrolyte dissociated by positively charged cations and negatively charged anions, external electric field oriented to be achieved and the counter electrode moves to the discharge thereon. Belong to the ion conductive electrolyte conductivity, the size of which increases with increasing temperature. It must be in the ion-conductive electrolysis electrode interface, causing the material (electrolyte-related) change. Generally rely free electron conductive metal conductor is a first type of conductor, and said second electrolyte solution and melt type conductor.

conductive factors

conductive factors affect the degree of ionization has, conductivity, ion mobility, migration of ions, ionic strength and ion activity.

The degree of ionization

to achieve ionization equilibrium, the electrolyte is more than the number of molecules to the total number of ionized molecules, expressed as a percentage. Ionization degree, showing ions generated by dissociation of more conductive ability. At a certain temperature, the degree of ionization of the electrolyte decreases as the concentration increases. The quantitative relationship between the degree of ionization, ionization constants, and concentrations determined by the law of diluted Chinese Oersted. Experiments show that a small degree of ionization of weak electrolytes, dilute well obey the law of the strong electrolyte substantially does not obey the law of dilute, because of the strong electrolyte is actually almost completely ionized. Solution in the power balance is not a problem. Due to the strong electrolyte solution there is a strong ionic interaction (except infinite dilution solution), the degree of ionization strong electrolyte which does not reflect the real situation ionization. Thus, said the ionization of the strong electrolyte is apparent degree of ionization.



inverse of resistance, conductance is consistent with the general meaning of the electrical engineering. Conductivity of the electrolyte solution there are two ways: as the specific conductance and the equivalent conductance. It refers to specific conductance of 1 cm2 electrode area, electrode distance of 1 cm conductance of the electrolytic solution. When the two means between two parallel electrodes separated by 1 cm of a solution containing 1 gram equivalent conductance of the electrolyte.

ion mobility

is the potential gradient between two electrodes when the moving speed of ions 1V / cm, also known as ion absolute movement speed. Ion mobility decreases with increasing concentration of the solution, with increasing temperature. The larger the ion mobility of the electrolyte, which is the equivalent conductance greater.

ion transference number

a certain amount of power delivered ion transport, by accounting fraction of the total amount of solution, also known as an ion transmission fraction. Two kinds of ion mobility is very different, it is also a great difference between the number of migration. Industrial electrolysis, according to the size of the mobility, which determines the concentration of ion-conductive charge near the electrode changes and how much, according to the electrolysis conditions as a control.

+ Activity

ion concentration after correction, also known as the effective concentration, equal to the product of the actual ion concentration and activity coefficient. Specific activity and activity coefficient is equal to the concentration. Processing extremely dilute solution outside, because there are complex interactions between the molecules and the ion flux and the solution so that the concentration is not equal to the ion activity, i.e. activity coefficient is not equal to 1. The introduction of the concept of ion activity, i.e., instead of the ion concentration of the ion activity, can make some thermodynamic formula applies only to the ideal solution can also be used for the actual solution.

ionic strength

All concentrations of various ions in solution by the sum of the square of half of its price. Average ion activity coefficient decreases with increasing ionic strength, and the higher the valence of the ions, the more reduced. Ionic strength to a certain extent reflects the strength of the interaction between the ions.

common electrolyte

strong electrolyte

acid: HCl, HBr, HI, H 2 SO 4 , HNO 3 , HClO 3 , HClO 4 like

alkali: NaOH, KOH, Ba ( OH) 2 , Ca (OH) 2 like

majority meltability salts: such as NaCl, (NH 4 < / sub>) 2 SO 4 , Fe (NO 3 ) 3 like

weak electrolyte

weak acids: HF, HClO, H 2 S, H 2 SO 3 , H 3 PO 4 , H 2 CO 3 like

weak base: NH 3 · H 2 O, Fe (OH) 3 , Al (OH) 3 , Cu (OH) 2et

few salts: HgCl 2 , lead acetate and

water (very weak electrolytes)

Related Articles