AP Chemistryeasymcq1 pt
Why do reaction rates generally decrease over time?
A.Reactant concentrations fall
B.The temperature falls
C.Catalysts are used up
D.Products block the reactants
Explanation
Core Concept
Fewer reactant particles remain, so collisions become rarer and the rate drops. This is why rate laws multiply reactant concentrations.
Correct Answer
AReactant concentrations fall
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