The conversion of molecules of A to B follows a second order kinetics. Doubting the concentration of A will increase the rate of formation of B by a factor of:
Correct answer: C. 4
- A. 2
- B. 1/2
- C. 4
- D. 1/4
Explanation
In a second-order reaction, the rate of reaction is proportional to the square of the concentration of the reactant(s). If you double the concentration of reactant A, the rate of the reaction will increase by a factor of 22, which is 4. In mathematical terms, if the rate equation for the reaction is given as: Rate = k[A]2 Where [A] is the concentration of reactant A and k is the rate constant, then if you double the concentration of A ([A] initial becomes 2[A]), the new rate would be: New Rate = k (2[A])2 = 4 k [A]2 So, the rate of formation of B will increase by a factor of 4 if the concentration of reactant A is doubled in a second-order reaction.
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Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.
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