Answer :
Final answer:
The decomposition pressure of limestone reaches 1 atm at temperatures above 835°C, signifying the formation of quicklime and carbon dioxide.
Explanation:
The decomposition pressure of limestone reaches 1 atm at a temperature above 835°C. The transition temperature where calcium carbonate (CaCO3) converts to calcium oxide (CaO), commonly known as quicklime, and carbon dioxide (CO2) is called the equilibrium temperature. It's important to note that the actual decomposition begins gradually above 700°C and becomes significant at temperatures above 835°C, where the pressure of the produced CO2 becomes higher than 1 atm, implying that the equilibrium favors the products of decomposition.
This temperature is an approximate value because the assumption that enthalpy (ΔH°) and entropy (ΔS°) changes are independent of temperature is a simplification. Nonetheless, this is the standard temperature range for the manufacturing of quicklime, where the reaction is driven towards the products by continuously removing CO2 following Le Chatelier's principle.
