Calcium oxide (CaO) readily reacts with carbon dioxide (CO2) and water (H2O).
Reactions of Calcium Oxide
Calcium oxide, also known as quicklime or burnt lime, is a highly reactive compound. Its primary reactions involve:
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Reaction with Water: Calcium oxide reacts vigorously with water in an exothermic reaction, producing calcium hydroxide (Ca(OH)2), also known as slaked lime. This process is called slaking or hydration.
CaO (s) + H2O (l) → Ca(OH)2 (s) + Heat
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Reaction with Carbon Dioxide: Calcium oxide absorbs carbon dioxide from the atmosphere, gradually converting into calcium carbonate (CaCO3). This reaction is crucial in carbon capture and various industrial processes.
CaO (s) + CO2 (g) → CaCO3 (s)
Applications Based on Reactivity
The reactivity of calcium oxide with water and carbon dioxide is exploited in several applications:
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Mortar Production: Calcium hydroxide, produced by reacting calcium oxide with water, is a key ingredient in mortar. It reacts with atmospheric carbon dioxide over time to form calcium carbonate, which hardens the mortar.
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Industrial Processes: Calcium oxide is used in various industrial processes, including steelmaking, paper manufacturing, and water treatment. Its ability to react with acids and absorb impurities makes it a versatile chemical.
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Carbon Capture: Calcium oxide can be used to capture carbon dioxide from flue gases. The resulting calcium carbonate can then be processed for further use or storage.
Table Summarizing Reactions
| Reactant | Product(s) | Reaction Type | Notes |
|---|---|---|---|
| Water (H2O) | Calcium Hydroxide (Ca(OH)2) | Exothermic | Used in making slaked lime; generates significant heat. |
| Carbon Dioxide (CO2) | Calcium Carbonate (CaCO3) | Combination | Gradual reaction; used in carbon capture and mortar hardening. |
