Why does the chemical and chemical properties change before and after the reaction?
At present, the role of the catalyst has not yet fully understood. In most cases, it is believed that the catalyst itself and the reactants participate in the chemical reaction, reducing the activation energy required for the reaction. Some catalytic reactions are due to the formation of a very easy decomposition of the "intermediate", the decomposition of the catalyst to restore the original chemical composition, the original reactant becomes a product. Some catalytic reactions are due to adsorption, adsorption can only be in the catalyst surface of the most active area (called the active center) carried out. The greater the area of the active site, the greater the activity of the catalyst. Reactants such as impurities,
A catalyst that accelerates the chemical reaction, called a positive catalyst; a catalyst that slows the chemical reaction, called a negative catalyst. For example, the hydrolysis of esters and polysaccharides, commonly used inorganic acid as a positive catalyst; sulfur dioxide oxidation of sulfur trioxide, commonly used vanadium pentoxide as a positive catalyst, this catalyst is solid, the reactants for the gas, the formation of multi-phase catalytic, , Vanadium pentoxide is also called catalyst or contact agent; edible oil by adding 0.01% to 0.02% gallate n-propyl ester,
The catalyst will induce chemical reactions to change, leaving the chemical reaction faster or in a lower temperature environment for chemical reactions.
Definition: According to the definition proposed by IUPAC in 1981, the catalyst is a substance that accelerates the rate of the reaction without changing the standard Gibbs free enthalpy change of the reaction. This effect is called catalysis. Involving the presentation of the catalyst for the catalytic reaction
Catalysts are homogeneous catalysts with heterogeneous catalysts. The heterogeneous catalyst exhibits a reaction in a different phase (e.g., a solid catalyst in a liquid mixing reaction) and a homogeneous catalyst is a reaction in the same phase (for example, a liquid catalyst in a liquid mixing reaction). A simple heterogeneous catalytic reaction involves the addition of a reactant (or en-ch: substrate; zh-tw: subject) adsorbed on the surface of the catalyst, and the bond within the reactant causes a new bond due to the fragility of the bond, But because of the product and the catalyst between
