Question

What is Pseudo first order reaction? Derive integrated rate law equation for zero order reaction.

Hint:

Pseudo first order simplifies kinetics; zero-order reactions have constant rates, common in catalyzed reactions.

Answer 1

Pseudo First Order Reaction: A reaction that is second order (or higher) but appears first order due to one reactant in large excess, keeping its concentration nearly constant. Example: Hydrolysis of ester in water (\( \text{H}_2\text{O} \) in excess).
Zero Order Integrated Rate Law: For a zero-order reaction \( A \to \text{products} \), rate = \( k \).
\[ -\frac{d[A]}{dt} = k. \] Integrate: \( \int_{[A]_0}^{[A]} d[A] = -k \int_0^t dt \).
\[ [A] - [A]_0 = -kt \quad \Rightarrow \quad [A] = [A]_0 - kt. \]