Final answer:
To determine the rate constant k, use the rate law expression with values from an experiment to solve for k. Rearrange the rate law to isolate k and ensure that the calculated k has the correct units to match the rate's units, typically mol/L/s.
Step-by-step explanation:
To determine the value of the rate constant k (often referred to as kobs when referring to the observed rate constant), initially you need to have the rate law expression for the chemical reaction.
Once you have the rate law, use the experimental data provided from an experiment to solve for k. For example, if your rate law is rate = k[NO]²[H₂] and the reaction is third-order overall (sum of exponents equals 3), you would plug in the values from the experiment into the rate law.
If Experiment 2 provides a rate and concentrations, you would solve for k by rearranging the equation to k = rate / ([NO]²[H₂]). Make sure to calculate the correct units for k which balances the equation so that the rate is expressed as mol/L/s.
The complete question is: What is the value of the rate constant, k, using kobs? is: