Final answer:
To determine the rate law expression and the value of the rate constant k, reactant concentrations and reaction orders are analyzed using experimental data. A proportion of rate laws from different trials helps find reaction orders, and data is then used to calculate k.
Step-by-step explanation:
To determine the rate law expression and the value of the rate constant (k) for a chemical reaction, you need to analyze experiment data that shows how the rate of the reaction depends on the concentrations of the reactants. The rate expression follows the form rate = k[A]m[B]n, where A and B are reactants, m and n are the reaction orders, and k is the rate constant. Here are the general steps for determining the rate law and calculating the value of k:
Keep the concentration of one reactant constant while varying the other to find the reaction order for each reactant.
Construct a proportion using the rate laws from different trials to find the reaction orders.
Insert the known data into the rate law expression and solve for the value of the rate constant k, making sure the units match the required units for rate (mol/L/s).
Once you have determined the reaction order for each reactant and obtained the value of k, you can write the complete rate law for the reaction.