Use this chemistry calculator to reproduce a named relationship with explicit quantities and units for study, laboratory planning, or an independent numerical check.

Initial concentration (mol/L)

Initial reactant concentration [A]₀ in mol/L.

Rate constant (1/s)

First-order rate constant in s⁻¹.

Time (s)

Elapsed time.

Solve the first-order integrated rate law ln([A]₀/[A]) = k·t for the remaining concentration. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Concentration (mol/L)

Concentration [A] after the elapsed time.

• Kinetic results assume the selected rate law and constant conditions over the calculation interval. Reaction order, catalyst state, mixing, temperature, competing pathways, and transport limitation must be established independently.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check units and significant figures, compare the result with limiting cases, and use measured or source-specific constants where available. Laboratory, safety, and regulatory decisions require validated methods and appropriate uncertainty analysis.

• Second Order Integrated Rate Calculator

  Solve the second-order integrated rate law 1/[A] = 1/[A]₀ + k·t for the remaining concentration.

• Zero Order Integrated Rate Calculator

  Solve the zero-order integrated rate law [A] = [A]₀ − k·t for the remaining concentration, clamped at zero.

• Decay Half-Life Calculator

  Solve the half-life from an initial amount, a remaining amount, and the elapsed time as t½ = t·ln2 / ln(N₀/N).