What this calculator does
Rate constant from concentration vs. time works out reaction rate constant k from concentration data, for zero, first or second order kinetics. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
The inputs explained
| Field | What to enter |
|---|---|
| Reaction order | Choose from Zero order, First order, Second order. |
| Initial concentration [A]₀ (mol/L) | A number, measured in mol/L. Starts at 1. |
| Concentration at time t [A] (mol/L) | A number, measured in mol/L. Starts at 0.5. |
| Elapsed time (s) | A number, measured in s. Starts at 100. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with initial concentration [a]₀
Every other input is held at the calculator’s starting values while initial concentration [a]₀ varies. Select any row to load that scenario into the calculator.