Here are the essential concepts you must grasp in order to answer the question correctly.
Le Chatelier's Principle
Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change. In the context of the decomposition of lead(IV) oxide, increasing the temperature will favor the endothermic reaction, shifting the equilibrium towards the products (PbO and O2), thus reducing the amount of PbO2 present.
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Equilibrium Constant (K)
The equilibrium constant (K) quantifies the ratio of the concentrations of products to reactants at equilibrium for a given reaction at a specific temperature. For the decomposition of PbO2, the value of K will change with temperature, influencing how much PbO2 remains in each vessel after heating. A higher temperature typically increases K for endothermic reactions, indicating more products are formed.
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Effect of Temperature on Reaction Rates
Temperature affects the rate of chemical reactions, with higher temperatures generally increasing reaction rates. In the case of the decomposition of PbO2, heating to 400°C accelerates the reaction, leading to a faster conversion of PbO2 to PbO and O2. This increased rate of reaction is crucial for understanding why vessel B, if designed differently (e.g., with more surface area or different conditions), may have less PbO2 remaining compared to vessel A.
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