The rate constant is a number that describes the rate at which a chemical reaction proceeds, and is usually displayed as k1/k2, where k1 is the reaction rate constant and k2 is the activation energy.
The rate constants are important for researchers because they can help scientists use a reaction as a way of understanding reaction kinetics and the mechanism of reactions in general. An excellent source of information on reaction rate constants is the Kinetics Database from the National Institute of Science and Technology (NIST) in the United States. This database is free and public, but the information is limited to reactions with a reaction rate constant of about 10.
The Kinetics Database is a great resource for scientists, chemists, and researchers in general. The database is organized by the type of reaction (which means, of course, that if the reaction is of interest to you, perhaps you can find it in there). In this case, what we’re dealing with are reactions where the energy of the reacting species goes up as the reaction progresses. These are called thermodynamic reactions.