Q56
neet_2026_03_may_morning
Rate Constant Units
Match List I with List II :
Choose the correct answer from the options given below :
| List-I (Order of reaction) | List-II (Unit of rate constant) |
|---|---|
| A. Zero order | (I) mol⁻¹ L s⁻¹ |
| B. First order | (II) mol⁻² L² s⁻¹ |
| C. Second order | (III) s⁻¹ |
| D. Third order | (IV) mol L⁻¹ s⁻¹ |
Solution
Related Formula
Unit of rate constant (k) = ( molL)¹⁻ⁿ s⁻¹where n is the order of reaction.
Core Logic
For zero order reaction n = 0: Unit = ( molL)¹ s⁻¹ = mol L⁻¹ s⁻¹ (Matches IV)
For first order reaction n = 1: Unit = ( molL)⁰ s⁻¹ = s⁻¹ (Matches III)
For second order reaction n = 2: Unit = ( molL)⁻¹ s⁻¹ = mol⁻¹ L s⁻¹ (Matches I)
For third order reaction n = 3: Unit = ( molL)⁻² s⁻¹ = mol⁻² L² s⁻¹ (Matches II)
Step 1: Final Match
A arrow IV B arrow III C arrow I D arrow II (Note: Option 3 in the source is given as A-IV, B-III, C-I, D-II, although a typo in the raw text output says D-I, the logic leads to D-II).
Pattern Recognition
Every time order n increases by 1, the unit of k loses one power of concentration (mol/L). The base form is (mol/L)¹⁻ⁿ / s.
Chapter Mix
Class 12 Chemistry: Chemical Kinetics
