Question

Identify the order of reaction if the rate constant is k=2×10⁻²s⁻¹:

• A. Zero order
• B. First order
• C. Second order
• D. Half order

Answer 1

The Correct Option is B

The units of the rate constant directly indicate the order of a reaction. The given rate constant, k, is 2×10⁻²s⁻¹.

The typical units for rate constants of various reaction orders are:

• Zero order: mol L⁻¹ s⁻¹
• First order: s⁻¹
• Second order: L mol⁻¹ s⁻¹
• Half order: These units are not standard or frequently encountered.

Since the units of k are s⁻¹, this signifies a first-order reaction. Consequently, the reaction is first order.