First of all, the chemical meaning is different

Kc stands for concentration balance. The equilibrium constant expressed by the concentration quotient of product to reactant at equilibrium is the empirical equilibrium constant Kc.

Kp stands for pressure balance number. The pressure quotient equilibrium constant of products to reactants at equilibrium is empirical equilibrium constant Kp or Kc.

Second, the problem-solving skills are different.

Kc should be calculated by the concentration of each gas. Therefore, when the concentration value in the topic is more detailed, Kc formula is generally used for calculation.

Kp shall be calculated according to the pressure of each gas. Therefore, when the gas pressure value in the topic is more detailed, Kp formula is generally used for calculation.

Note: the value of chemical equilibrium constant can judge the degree of reaction, and the expression of chemical equilibrium constant is related to the writing method of chemical equation. For the same chemical reaction, due to different writing methods, the stoichiometry of each reactant and product is different, and the equilibrium constants are also different, but these equilibrium constants can be converted to each other.

Extended data:

Factors affecting chemical equilibrium constants:

In middle school, it is generally believed that the chemical equilibrium constant is only related to temperature, and the equilibrium constant of endothermic reaction increases with the increase of temperature, while the exothermic reaction is the opposite. But strictly speaking, the chemical reaction equilibrium constant is a function of temperature and pressure, and the situation is different for different chemical equilibrium constants.

In gas phase reaction, all standard equilibrium constants are only functions of temperature. If a gas is an ideal gas, its empirical equilibrium constant is only a function of temperature. But for non-ideal gases, the equilibrium constant is affected by temperature and pressure.

Theoretically, any reaction involving condensed phase (solid or liquid) is a function of temperature and pressure. However, in the case of small pressure change range, the influence of pressure on the volume change of condensed phase can be ignored, that is, the influence of pressure on equilibrium constant can be ignored.

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