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Which of the following statements about chemical kinetics and catalysis is/are correct? (A) According to collision theory, the rate of a reaction is directly proportional to sqrt(T) * e^(-Ea/RT). (B) A catalyst cannot change the equilibrium constant or the equilibrium composition of a reaction mixture. (C) A good solid catalyst for heterogeneous catalysis should have a high magnitude of enthalpy of adsorption of reactants on its surface. (D) For reactions in liquid solutions, the solvent may strongly affect the rate constant.

1. A only
2. B only
3. C only
4. D only

Correct answer: B only

Solution

Statement A: Collision theory — rate = Z*P*e^(-Ea/RT), where collision frequency Z is proportional to sqrt(T). Rate is proportional to sqrt(T)*e^(-Ea/RT). CORRECT. Statement B: A catalyst lowers activation energy but does not alter the thermodynamics (delta-G, Keq). CORRECT. Statement C: Sabatier's principle states that catalytic activity is maximum at intermediate adsorption enthalpy (volcano plot). Too high enthalpy means reactants are stuck on the surface. INCORRECT. Statement D: Solvent polarity, dielectric constant, and hydrogen bonding can profoundly affect rate constants in solution. CORRECT. Statements A, B, D are correct; C is incorrect. Since the options list individual letters, the answer excluding C suggests A, B, or D individually. The most textbook-standard single correct statement here (and the one the question likely isolates) is B.

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