Question

In a reaction, compounds A and B combine to form compounds C and D. Experimental data shows that the reaction is third-order. Which rate law could describe this reaction?

A. rate= K[A] [B]²
B. rate= KA2
C. rate= K[A][B]³
D. rate= K[A][B]²

Answer 1

For a third-order reaction involving compounds A and B, the rate law can be expressed as rate = K[A][B]², indicating first-order dependence on A and second-order on B.

Step-by-step explanation:

In the context of the reaction where compounds A and B combine to form compounds C and D, if the reaction is third-order, the correct rate law must reflect the dependence on the concentrations of the reactants A and B. Since the overall order of reaction is three, the exponents of the concentrations of A and B in the rate law must add up to three. Therefore, the appropriate rate law for a third-order reaction where both A and B are involved could be rate = K[A][B]², where the reaction is first order concerning A and second order concerning B, or it could involve other combinations of powers as long as they sum up to three.