Pick your Calculation Method, enter values like Reaction Rate, Concentration [A], and Order of Reaction, and the Rate Constant Calculator works out your Rate Constant (k) — complete with correct units and Half-Life (t₁/₂) when applicable.
Rate Constant (k)
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Half-Life (t₁/₂)
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Units
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The rate constant can be calculated using two methods: from experimental rate law data (k = rate / [A]^m[B]^n) or from integrated rate law equations depending on the reaction order (zero, first, or second order).
The unit of rate constant depends on the overall reaction order: zero order (M/s), first order (1/s or s⁻¹), second order (1/(M·s) or M⁻¹s⁻¹), and so on.
No, the rate constant cannot be negative. It represents the proportionality constant in rate laws and must always be positive for forward reactions.
The rate constant is primarily affected by temperature (follows Arrhenius equation), the presence of catalysts, and the nature of the reactants. It is independent of concentration.
Half-life is the time required for the concentration of a reactant to decrease to half its initial value. For first-order reactions, t₁/₂ = 0.693/k.
Activation energy can be found using the Arrhenius equation: ln(k₂/k₁) = (Ea/R)(1/T₁ - 1/T₂), where you need rate constants at two different temperatures.
Reaction rate is the speed at which reactants are consumed or products are formed, while rate constant is a proportionality constant that relates reaction rate to reactant concentrations.
Temperature increases the rate constant exponentially according to the Arrhenius equation. Higher temperatures provide more energy to overcome the activation barrier, increasing k.