Which of the following best describes a partial reaction order in a rate law?

• A. A reaction order that is always zero for all reactants
• B. A reaction order that applies only to the overall reaction, not individual reactants
• C. A reaction order that is a non-integer value for a particular reactant
• D. A reaction order that is always an integer for every reactant

Answer: (C)

Verified step by step guidance

1. Understand that the reaction order in a rate law refers to the exponent to which the concentration of a reactant is raised in the rate equation.
2. Recognize that a partial reaction order specifically refers to the order with respect to an individual reactant, not the overall reaction order.
3. Recall that reaction orders can be integers (like 0, 1, 2) or non-integers (fractions or decimals), depending on the reaction mechanism and experimental data.
4. Identify that a partial reaction order being a non-integer means the rate depends on the concentration of that reactant raised to a fractional power, which often indicates complex reaction steps or intermediates.
5. Conclude that the best description of a partial reaction order is that it can be a non-integer value for a particular reactant, reflecting the nuanced dependence of the rate on that reactant's concentration.