In the reaction A +B → Products, if B is taken in excess, then it is an example of:
Correct answer: B. Pseudo first order reaction
- A. Second order reaction
- B. Pseudo first order reaction
- C. Zero order reaction
- D. First order reaction
Explanation
When one reactant is taken in excess compared to the other in a chemical reaction, the reaction effectively becomes pseudo-first order with respect to the limiting reactant. This is because the concentration of the limiting reactant significantly affects the overall rate of the reaction, while the concentration of the excess reactant remains relatively constant. So, if in the reaction A+B→Products, reactant B is taken in excess, the reaction would effectively behave as a first-order reaction with respect to reactant A. This is known as a pseudo-first order reaction. In summary, if B is taken in excess, it results in a pseudo-first order reaction with respect to A.
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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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