CBSE Class 12 · 2002 · Delhi · Chemical KineticsVery Short Answer

State any one condition under which a bimolecular reaction may be kinetically first order.

Answer: When one reactant is present in large excess, so its concentration stays practically constant (pseudo first order).

Solution

When one of the two reactants is present in large excess (e.g. water in a hydrolysis), its concentration remains virtually constant during the reaction; the rate then depends only on the other reactant, and the bimolecular reaction follows first-order kinetics — a pseudo first order reaction.

CBSE Class 12 Board · 2002 · Delhi · Subjective

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