The order of a reaction with respect to a particular reactant
Correct answer: B. is the power to which its concentration is raised in the experimentally determined rate equation
- A. is always equal to its coefficient in the balanced equation
- B. is the power to which its concentration is raised in the experimentally determined rate equation
- C. can never be zero
- D. is always a whole number
Explanation
Order is an experimental quantity and must be measured, because the balanced equation describes the overall stoichiometry while the rate depends only on the slow, rate determining step. This is why orders can be zero, fractional or even negative, none of which a coefficient can be. Only for a genuinely single step reaction do order and coefficient happen to agree.
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About Order of Reaction
Reaction order shows how the rate depends on the concentration of each reactant, as expressed in the rate law. Coverage includes zero, first and second-order reactions, integrated rate equations, half-life, units of rate constants and the distinction between overall order and molecularity.
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