When δ h 0, the spontaneous process begins and the process can move forward;
When δ h > 0, δ s <: 0，δ g
δH & lt； 0，δS & lt； 0 or δ h > 0, δ s >; The spontaneity of 0 reaction depends on temperature, with enthalpy change at low temperature and entropy change at high temperature. When Δ δG = 0, it is in equilibrium.
Obviously, the calcined limestone is δ h >: 0, δ s >: 0, it is calculated that under the conditions of 102.32kPa and 1 183K (i.e. 9 10℃), limestone can spontaneously and violently react, which needs to be spontaneously carried out at high temperature. As long as this temperature is maintained, the reaction will continue.
Extended data
1. In chemistry, spontaneous reactions and spontaneous processes limit conditions such as temperature and pressure, which is different from the "spontaneity" in the sociological field explained by dictionaries.
2. It is limited to judge the spontaneity of chemical reaction only from enthalpy change or entropy change. We should combine these two factors to understand the spontaneity of chemical reaction from the perspective of free energy.
3. Chemically, the reaction is spontaneous, that is, the reaction in one direction is significant, and chemically, the reaction in the opposite direction is almost impossible. From the point of view of chemical equilibrium, spontaneous reaction means that the chemical equilibrium constant is very large and the positive reaction is carried out thoroughly.
4. From the essence of chemical reaction, as long as the given external conditions can destroy the old chemical bonds and rearrange the atoms to form new chemical bonds, any chemical reaction can be carried out under the given conditions, just like nitrogen and oxygen can react, and the free energy theory explains that it is an unconscious reaction at any temperature.
In a word, Δ g = Δ h-t Δ s, as a criterion of chemical reaction spontaneity, must be a chemical reaction without doing non-volume work at constant temperature and pressure.
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