How can acetic acid be proven to be a weak electrolyte?

Experiments can be designed based on differences in the conductivity of strong and weak electrolytes. However, the following experiment can only be used to compare strong and weak electrolytes (for secondary schools, it can still be used to indicate which is strong and which is weak). The most accurate method is to determine the degree of ionization.

In addition, there is no absolute division of the strength of electrolytes, and there is no strict boundary between strong and weak electrolytes. For example, in middle school, sulfuric acid is considered a strong electrolyte and is completely ionized. But in fact, its secondary HSO4- ionization is also incomplete.

Experiment 1-1] Connect the instrument according to the device in Figure 1-9. Then the HCl, CH3COOH, NaOH, NaCl solution and ammonia solution under the same conditions (isothermal, isobaric, and isometric concentration) were poured into five beakers and turned on the power supply. Observe how bright the bulb glows.

The experimental results show that the bulb on the electrode connected to the CH3COOH solution and ammonia water is darker than that of the other three bulbs. It can be seen that their conductivity under the same conditions is not the same.

HCl, NaOH and NaCl solutions have stronger conductivity than CH3COOH solutions and ammonia. Why is that? We can analyze it from the structure of these substances and the changes that occur when they dissolve in water.

From the point of view of material structure, NaCl, NaOH, etc. are ionic compounds composed of anions and cations. When these substances are dissolved in water, the anions and cations detach from the crystal surface and are ionized to form freely moving hydrated anions and hydrated cations under the action of water molecules (Figures 1-10). For the sake of simplicity, hydrated ions are still usually denoted by ion symbols.

For example, the ionization equation for NaCl and NaOH is: NaCl==Na++Cl- NaOH==Na++OH - Not only ionic compounds, but covalent compounds like HCl do not conduct electricity in the liquid state, but after being dissolved in water, they can also be completely ionized into hydronium ions and chloride ions hydrate under the action of water molecules. HCl==H++Cl- Experiments have proved that in most aqueous solutions of salts, strong acids and strong bases, there are only hydrated ions and no solute molecules, and they are all ionized.

Electrolytes that are completely ionized into ions in an aqueous solution are called strong electrolytes. For example, NaOH, KOH, HCL, HNO3, H2SO4, NaCl, Kno3, etc., are all strong electrolytes. Electrolytes in which only a portion of the molecules in an aqueous solution ionize into ions are called weak electrolytes.

Weak acids and bases are weak electrolytes, such as CH3COOH, NH3·H2O, etc. Water is also a weak electrolyte.

Bottom line: because it is not completely ionized.

Sodium acetate isStrong electrolytes, not a weak electrolyte, because sodium acetate is inMolten stateIt can be completely ionized in aqueous solution, as long as it is ionizable in the molten state or ionizable in aqueous solution, one of the conditions is a strong electrolyte, so sodium acetate is a strong electrolyte

Learn chemistry well

1. Understand various reactions and chemical reactions.

Including reduction reaction, oxidation reaction, nano ridge.

Chemical reaction, decomposition reaction, acid-base neutralization reaction, etc. In chemical reactions, we must firmly grasp the valency.

Knowing this, I believe that it will not be difficult to react to this aspect.

2. Do as many experiments as possible if possible, practice is the only criterion for testing the truth, so experiments also account for a considerable proportion. You need to understand how to use some experimental equipment, for example, condensation insight seepage tubes.

Test tubes, iron frames, alcohol, etc. In addition, when doing experiments, you must pay attention to your own safety.

3. Pre-class preview, the teacher will often talk about the difficult points and easy to mix up in class, and before the teacher speaks, you must prepare for the preview.

4. Connect with life, learn knowledge points, and connect with actual life. For example, iron rusts because iron undergoes a slow oxidation reaction in the air.

It is a weak electrolyte, because the metal cation Pb2+ of lead acetate is not a typical active metal cation, and the polarization ability is relatively strong, and Pb2+ is a 9 17 electron configuration, which has a certain deformation, so that the compound is transformed from an ionic compound to a covalent compound, and the ionization in water is incomplete.

It is mainly used as a test strip to detect trace amounts of sulfur. Dissolve 1g of lead acetate in 20ml of deionized water, and soak 5mm 30mm filter paper strips into lead acetate solution to form acetic acid Doosan lead test paper. The test strip turns black when exposed to hydrogen sulfide gas or an acidic solution containing sulfide, verifying the presence of hydrogen sulfide or sulfide.

At present, in the production process of some Chinese medicinal materials (angelica, skullcap, etc.) and agricultural products (white fungus, shiitake mushrooms, etc.), in order to sterilize and bleach, so that the product is kept dry, the product will be sulfur fumigated with sulfur dioxide, so as to facilitate transportation and storage, and also improve the appearance quality, and facilitate sales, but this will leave sulfur dioxide on the traditional Chinese medicine or agricultural products that have been fumigated by sulfur, and sulfur dioxide is a substance harmful to the human body, and the main methods for detecting sulfur dioxide are spectrophotometry, fluorescence photometry, chemiluminescence method, Iodine dosimetry and chromatography, these methods are complex to operate, the experimental time is long, and some also need to use the experimental pin room instrument, which is not suitable for on-site rapid detection. The use of lead acetate test strips for testing greatly reduces the workload of experimenters and avoids the interference of many irrelevant factors.

It can also be used to prepare various lead salts (lead borate, lead stearate, etc.), antifouling coatings (lead acetate and potassium dichromate can be used to produce chrome yellow), water quality protection agents, pigment fillers, paint desiccant, fiber dyes and solvents for heavy metal cyanidation process.

In the textile industry, it is used as a raw material for tarpaulin to prepare lead soap waterproofing. In the electroplating industry, it is a luminescent agent for copper cyanide plating. In the pigment industry, lead acetate reacts with sodium alum, which is the basic raw material for the preparation of chrome (i.e., lead chromate).

It is used as a reagent for the determination of chromium and molybdenum trioxide in trioxan in chemical analysis. Lead acetate is also a dyeing aid in the fur industry.