Regarding the endothermic dissociation of CaCO3 inside a sealed container (CaCO3 ⇌ CaO + CO2), the partial pressure of CO2 rises if____________________?
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Answer: B. The temperature is increased
Explanation
Endothermic reactions absorb heat, meaning higher temperatures shift chemical equilibrium toward the product side. According to Van't Hoff equation, raising the temperature increases the equilibrium constant for endothermic processes. A higher equilibrium constant results in a greater equilibrium partial pressure of carbon dioxide in the container. Le Chatelier's principle states that stress applied to a system at equilibrium shifts it to counteract that stress. Thermal energy acts effectively as a reactant in endothermic chemical equilibrium systems like calcium carbonate dissociation. Calcium carbonate decomposes thermally into calcium oxide solid and carbon dioxide gas inside sealed enclosures.
Option A is incorrect because adding a catalyst speeds up reaching equilibrium without altering the equilibrium position. Option C dilutes the gas phase with inerts but changes total pressure rather than the thermal equilibrium constant directly. Option D is wrong because temperature increase clearly produces a definitive physical and chemical response.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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