Chemistry
Rate Constant Calculator
Find the rate constant k from a measured rate and reactant concentrations, with the correct units.
Your inputs
Change any value to update the result instantly.
Rate constant k
0.02 1/s
Overall reaction order
1
Units of k
1/s
Half-life at this starting concentration
34.6574 s
Integrated law for this order
ln[A]t = ln[A]0 − kt
Orders come from experiment, not from the balanced equation. The half-life shown uses the integrated law for the overall order you entered.
What this calculator does
Determines the rate constant k from a measured rate, the reactant concentrations and the experimental reaction orders.
What your result means
k measures how fast the reaction runs at that temperature; the units depend on the overall order, and the half-life shown follows the matching integrated rate law.
Formula and working
rate = k[A]^m[B]^n , so k = rate ÷ ([A]^m [B]^n)
- 1
Collect the inputs
Measured reaction rate = 0.004 mol/(L·s); [A] = 0.2 mol/L; Order in A (m) = 1; [B] (use order 0 if absent) = 1 mol/L; Order in B (n) = 0
- 2
Apply the formula
rate = k[A]^m[B]^n , so k = rate ÷ ([A]^m [B]^n)
- 3
Result
Rate constant k = 0.02 1/s
Frequently asked questions
Symbols and assumptions
- k
- Rate constant
- m, n
- Orders with respect to A and B
- rate
- Reaction rate in mol per litre per second
- • Orders come from experiment, not from the balanced equation.
- • Temperature is constant while the rate is measured.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Fractional or negative orders and complex mechanisms are outside this simple rate law. k changes with temperature, as described by the Arrhenius equation.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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