alleryWhich of the following statements about order and molecularity is correct?
AMolecularity can be zero or a fraction
BOrder is defined only for elementary reactions
COrder can be zero or a fraction, molecularity cannot
DMolecularity is always equal to overall order
Answer & Solution
Correct answer: C. Order can be zero or a fraction, molecularity cannot
1. Order is an experimental quantity and can be 0, a fraction, or an integer.
2. Molecularity counts colliding species, so it must be a positive integer (1 to 3).
3. Thus order may be zero or fractional while molecularity cannot.
4. Order applies to complex reactions too, so option B is wrong.
_Source: syllabus Chemistry Ch 3 "Chemical Kinetics", p.10_
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