Generally speaking, the chemical equation of acid-base reaction is: acid+alkali → salt+water. For example, when hydrochloric acid reacts with sodium hydroxide (sodium hydroxide is a common alkali), sodium chloride (salt) and water: HCl+NaOH → NaCl+H2O will be obtained. In this reaction, hydroxyl ion (OH-) in sodium hydroxide and hydrogen ion (H+) in hydrochloric acid combine to produce water and sodium chloride (salt) at the same time.
The acid-base neutralization reaction is characterized by the formation of water, because the reaction between acid and base is neutralized by the combination of hydrogen ion (H+) and hydroxide ion (OH-). This neutralization reaction process can adjust the pH value of the solution, so that its pH value gradually approaches neutrality.
Common application examples of reaction between acid and base
1, neutralization reaction: One of the main applications of acid-base reaction is neutralization reaction. This reaction can be used to adjust the pH of the solution and realize neutralization treatment. For example, in the process of sewage treatment, acidic wastewater and alkaline wastewater are neutralized to achieve neutrality for better discharge or further treatment.
2.pH regulator: Many products and chemical experiments need to control the pH value of the solution. The reaction between acid and alkali can be used as a pH regulator. For example, in the beverage and food industry, acid and alkali are added to adjust the taste and extend the shelf life.
3. Cleaning agents and detergents: The reaction of acid and alkali can be used to make cleaning agents and detergents. For example, some cleaners use acidic substances to remove scale, metal oxides and hard water deposits; Some detergents use alkaline substances to remove grease and protein residue.
4. Medical field: In the medical field, the reaction of acid and alkali is widely used in the preparation and preparation of drugs. For example, the solubility, stability and release rate of drugs can be controlled by adjusting the pH of the solution.
5. Acid-base indicator: An acid-base indicator is a chemical substance that indicates the pH of a solution by changing its color. It is realized by the reaction of acid and alkali. Common acid-base indicators are phenolphthalein and bromophenol blue.
The reaction between acid and alkali is widely used in many fields, including sewage treatment, pH adjustment, detergent preparation, drug preparation and acid-base indication.